It's always a sad moment when you realize that college football's regular season is more than halfway done, but it should still be a fun week with lots of exciting games on tap. Six of the top 10 teams in the country play ranked opponents, and 13 top 25 teams face challenges on the road.

Here is what to watch this week in college football:

#13 Mississippi State (7-0) at #1 Alabama (7-0)

[Saturday at 8:30 p.m. on ESPN]

After steamrolling through its first seven opponents, the Crimson Tide now gets to the meat of its schedule with a three-game stretch vs. #13 Mississippi State, at #6 LSU and vs. #22 Texas A&M. Thus far, Alabama hasn’t really been challenged, outscoring its opponents by almost 33 points per game. The Tide defense has been as good as we’ve seen in years, ranking first in almost all defensive categories. But while the defense understandably gets the publicity, the Alabama offense has been no slouch either, scoring 40+ in five of seven games this year. Quarterback A.J. McCarron leads the nation in pass efficiency and the offense ranks 14th nationally in scoring. This week, however, they’ll be challenged by a Mississippi State defense that ranks ninth nationally in both scoring defense and interceptions. On offense, MSU running back LaDarius Perkins leads the SEC in rushing but will face a Crimson Tide defense that is giving up less than 59 rushing yards per game. The Bulldogs are off to their best start since 1999, but their three league wins have come against teams that are a combined 0-14 in SEC play. Mississippi State has lost four straight to Alabama and has never put up more than 10 points in a game during that stretch.

Colorado (1-6) at #2 Oregon (7-0)

[Saturday at 3 p.m. on PAC-12 Network]

Colorado gave up 458 yards and 50 points last week at USC, and things aren’t likely to get much better this week on the road at Oregon. The Ducks are second in the nation in scoring offense (51 points per game) and fourth in rushing. They should have little difficulty against a young, beat up Buffs defense that is next-to-last in the nation in scoring defense, giving up almost 43 points per game. Barring a Rocky Mountain-sized miracle, this one should be over early.

#3 Florida (7-0) vs. #12 Georgia (6-1)

[Saturday at 3:30 p.m. on CBS; game played in Jacksonville, FL]

Thanks to a front-loaded SEC schedule, Florida can clinch the SEC East before the end of October with a win over the Bulldogs this weekend. The Gators are 7-0 thanks to a stifling defense that ranks seventh in total defense and fourth in scoring. This week, however, they’ll face a Bulldogs offense that is second in the conference in total offense. Georgia quarterback Aaron Murray, who has already thrown for over 1,900 yards and 16 touchdowns this season, is coming off a career day with 427 yards and four touchdowns last week against Kentucky. However, he likely won’t be helped this week by a Bulldogs defense that has given up at least 300 yards in every game this year and 20+ points in all but one. Florida is certainly no offensive juggernaut (102nd nationally in total yards), but has shown the ability to put up points, scoring 30+ points in four of its last five games. Georgia beat Florida last year, but has won just 3 of the last 14 meetings.

#15 Texas Tech (6-1) at #4 Kansas State (7-0)

[Saturday at 3:30 p.m. on FOX]

After moving to the top of the Heisman contender list, Kansas State quarterback Collin Klein will look to keep the Wildcats in the national title mix against a surprising Red Raider squad that still has hopes for a Big 12 championship. Klein is coming off a career day against West Virginia (323 passing yards and seven total touchdowns), but will face a much tougher task with Texas Tech, currently ranked seventh nationally in total defense. The Red Raider defense has held five opponents to 14 or fewer points, but was lit up in those other two games (41 by Oklahoma and 53 by TCU). However, even if the defense does have a down day, Texas Tech showed last week (56-53 victory) that their offense is good enough to win a shootout. Quarterback Seth Doege has thrown 15 touchdowns in his last two games and leads the nation in scoring. The Wildcats are seeking their first 8-0 start since 1999.

#5 Notre Dame (7-0) at #8 Oklahoma (5-1)

[Saturday at 8 p.m. on ABC]

Two of college football’s premier programs will meet in a game with serious national-title implications. Notre Dame features its best defense since its 1988 national-championship team and has not given up a rushing touchdown this season. However, they have yet to face an offense with the firepower of Oklahoma. After struggling in an early loss to Kansas State, Sooners quarterback Landry Jones has excelled of late, throwing for 880 yards, seven touchdowns and one interception in his last three games. The Sooners rank 17th in total yards and seventh in scoring this season, but will face their toughest defensive test yet against the Fighting Irish and star linebacker Manti T’eo. After missing last week’s game with a concussion, Notre Dame starting quarterback Everett Golson is expected to be back under center this week. Notre Dame has won eight of nine all-time meetings with the Sooners, but the two have not played since 1999.

#6 LSU, Bye

LSU gets a very well-timed bye to prepare for next week’s big showdown with #1 Alabama.

#7 Oregon State (6-0) at Washington (3-4)

[Saturday at 10:15 p.m. on PAC-12 Network]

After missing two games with a left knee injury, Oregon State quarterback Sean Mannion is expected to be back under center for the Beavers this week. Before his injury, Mannion ranked sixth in the nation in passing (339.5 yards per game), so he should provide an upgrade to a Beavers offense that managed just 227 total yards last week. Washington’s offense, which ranks 105th in total yards and 107th in scoring, could be in for another tough week against Oregon State, which is giving up just 16.5 points per game and ranks fifth in the nation in rush defense. The Beavers have won seven of the last eight in this series, but should be wary of a Washington team that has been tough at home this season, upsetting Stanford and playing USC close.

#9 Ohio State (8-0) at Penn State (5-2)

[Saturday at 5:30 p.m. on ESPN]

Neither team is eligible to play in the Big Ten title game, but these might actually be the best two teams in the conference. Ohio State dodged one bullet last week with an overtime win over Purdue and got an even bigger scare when star quarterback Braxton Miller was rushed to the hospital with an apparent head injury. However, tests revealed no serious injury and, despite a sore neck, Miller is expected to start this week. The Buckeyes are 8-0 for the first time since 2007 behind Miller, who is second in the Big Ten in total offense and needs just 41 rushing yards to become the first Ohio State quarterback ever to rush for 1,000 yards. This week, however, he’ll be tested by a Penn State defense that has given up less than 250 yards in three of its last four games. After dropping their first two, the Nittany Lions have rebounded with a five-game winning streak in which they’ve outscored their opponents by over 20 points per game. Senior quarterback Matt McGloin has already set a career high in passing yards and leads the Big Ten in passing yards per game (255.4).

#10 Southern Cal (6-1) at Arizona (4-3)

[Saturday at 3:30 p.m. on ABC/ESPN2]

After demolishing Colorado last week, the Trojans should have a slightly tougher challenge this week against an Arizona offense with the ability to play with them in a shootout. The Wildcats are putting up 39.1 points per game, good for fourth nationally. But they have had trouble stopping their opponents, giving up 30.4 points and 465 yards per game. As such, Matt Barkley and the receiving tandem of Marquise Lee and Robert Woods should be able to find success through the air. Lee leads the PAC-12 in receptions and receiving yards, while Woods leads the conference in touchdown catches. The Trojans have won nine of the last ten against Arizona and are seeking their first five-game winning streak since 2008.

Duke (6-2) at #11 Florida State (7-1)

[Saturday at 3:30 p.m. on ESPNU]

Duke is already bowl-eligible for the first time since 1994, but has its sights set even higher as the Blue Devils control their own destiny in the ACC Coastal division. However, history is not on their side this week as the Devils are 0-17 all-time against Florida State and have not beaten a ranked team on the road since 1971. Duke’s defense has given up almost 28 points per game (73rd nationally) this year and will be facing a Seminoles offense that is scoring over 44 per game and has scored 49 or more points five times this year. However, Florida State will be without star running back Chris Thompson, who will be out for the year after suffering a torn ACL last week. Thompson had been on a pace to become the Seminoles’ first 1,000-yard rusher since Warrick Dunn in 1996. Even without Thompson, Florida State should be able to control Duke with a defense that ranks second in the nation.

#14 Clemson (6-1) at Wake Forest (4-3)

[Thursday at 7:30 p.m. on ESPN]

The Tigers are averaging almost 41 points and 493 yards per game this year. But last week against Virginia Tech, when the offense was held to its lowest total in almost two years (295 yards), it was the defense that stepped up big, forcing four turnovers, returning an interception for a touchdown and giving up the fewest points they have to any FBS opponent this season. This week, however, the Clemson offense should be able to return to form against a Demon Deacons defense that has given up an average of 405 yards and 28 points per game (73rd and 74th in the country, respectively). Wake Forest has lost three in a row in this series, but has won three of the last five played at home.

Cincinnati (5-1) at #16 Louisville (7-0)

[Friday at 8 p.m. on ESPN2]

Although Cincinnati was upset by Toledo last week, both teams come into this game undefeated in conference play and with their BCS hopes very much alive. Bearcats signal caller Munchie Legeaux will look to find success against a Louisville defense that ranks 45th nationally in pass defense and has given up 14 passing touchdowns this season. But he’ll go toe-to-toe with Louisville quarterback Teddy Bridgewater, who is third in the nation in completion percentage (73.4%). Cincinnati has won the last four matchups with Louisville and has nine of their last ten against ranked conference opponents.

Tennessee (3-4) at #17 South Carolina (6-2)

[Saturday at 12 p.m. on ESPN]

After back-to-back road losses, the Gamecocks will look to regroup at home versus a Tennessee squad that has lost 11 of its last 12 conference games. USC running back Marcus Lattimore was injured in the LSU game and saw only limited action last week against Florida. But he is expected to be near full strength this week against a Vols defense that is 89th in the nation in rush defense.

Kent State (6-1) at #18 Rutgers (7-0)

[Saturday at 3:30 p.m. on SportsNet New York/Mid-Atlantic Sports Network]

Rutgers ranks third nationally in rushing defense, but should face a tough test from a potent Kent State attack that averages over 210 yards per game on the ground. Kent State is 6-1 and is angling for the school’s first bowl invite since 1972. A win this week would give the Golden Flashes their longest winning streak in 72 years. The Scarlet Knights, are off to their best start since 2006.

Washington State (2-5) at #19 Stanford (5-2)

[Saturday at 6:15 p.m. on PAC-12 Network]

Stanford running back Stepfan Taylor rushed for a career-high 189 yards last week against Cal. He’ll look for another big game against a Cougars defense that is next-to-last in the PAC-12 at defending the run. Washington State has lost four straight games and has given up an average of 30.4 points per game in that stretch. The Cougars have lost 18 in a row against top 25 teams, while Stanford has a 13-game home winning streak against unranked opponents.

#20 Michigan (5-2) at Nebraska (5-2)

[Saturday at 8 p.m. on ESPN2]

After needing a come-from-behind rally to beat Northwestern, Nebraska finds itself in another must-win position in a game that could well determine the outcome of the Big Ten Legends division. Michigan was held without a touchdown in last week’s 12-10 win over Michigan State, but star quarterback Denard Robinson should be able to have success against a Nebraska defense that has been prone to giving up big plays. Nebraska features the top offense in the conference (sixth nationally in rushing, 13th in scoring) but will face a Wolverines defense that has rebounded since their early season blowout by Alabama. Nebraska has struggled with turnovers this season and will need to do a better job holding on to the ball if they want to keep the dangerous Robinson off the field.

#21 Boise State (6-1) at Wyoming (1-6)

[Saturday at 3:30 p.m. on CBS Sports Network]

Boise State ranks sixth in the nation in scoring defense, and should have little trouble with a Cowboys offense that ranks 86th in total offense and has been held under 30 points five times this year. Wyoming will be without head coach Dave Christensen, who has been fined and suspended for one game following an obscenity-filled tirade at Air Force coaches after their Oct. 13 game. The Broncos have won 47 straight games in the month of October, a streak dating back to 2001. They are 6-0 all-time against Wyoming.

#22 Texas A&M (5-2) at Auburn (1-6)

[Saturday at 7 p.m. on ESPNU]

A&M’s offense was largely held in check by LSU, but they should be able to return to form against an Auburn defense that is in the bottom half of the SEC including almost all defensive categories. However, as bad as the Tigers’ defense is, the offense is even worse—ranking last in the nation in both total offense and scoring offense. Texas A&M, which ranks ninth in the nation in total offense, should have little trouble racking up big numbers this week. Auburn is the first team in the history of the AP Poll, which dates back to 1936, to go from national champions to 1-6 in just two years. This is the Tigers’ worst start in 60 years.

#23 Ohio (7-0) at Miami, OH (3-4)

[Saturday at 3:30 p.m. on ESPN Gameplan]

After a bye last week, Ohio returns to action with their first opportunity since 1968 to play as a ranked team. Four of the Bobcats’ victories have been by seven or fewer points, but they should be able to put up bigger numbers against a Miami team that has lost its last two games by a combined 89-26. Ohio has won the last six meetings against the RedHawks.

#24 Louisiana Tech (6-1) at New Mexico State (1-6)

[Saturday at 8 p.m. on ESPN Gameplan]

Louisiana Tech quarterback Colby Cameron has thrown an NCAA-record 275 passes without an interception this season. The Aggies have gotten only two interceptions this year, so Cameron should have a good opportunity to extend his own streak.

#25 West Virginia, Bye

After back-to-back blowout losses, the Mountaineers get a week off to try to stop the bleeding and prepare for next week’s contest against fellow Big 12 newcomer TCU.