Posted by ESPN.com's Adam Rittenberg
These were by far the toughest rankings to date, as things get very tricky after the top two.
1. Penn State (6-0, 2-0) -- The Nittany Lions won with their head coach (Joe Paterno) in the press box and their flashy offense struggling to reach the end zone. They didn't earn many style points against Purdue, but a solid defensive performance and smart play by quarterback Daryll Clark keeps Penn State as the team to beat.
2. Ohio State (5-1, 2-0) -- Nothing came easy for the Buckeyes in Camp Randall Stadium, but a gutsy performance by freshman quarterback Terrelle Pryor, junior running back Chris "Beanie" Wells and several others secured a huge road win. Penn State has looked more impressive this season, but Ohio State is closing the gap thanks to Wells and Pryor.
3. Michigan State (5-1, 2-0) -- The Spartans proved they can win without a Heisman-caliber performance from senior running back Javon Ringer. Quarterback Brian Hoyer stepped up nicely and will need another strong effort on the road this week against undefeated Northwestern. A win against the Wildcats puts the Spartans in the league title mix with Ohio State coming to East Lansing on Oct. 18.
4. Northwestern (5-0, 1-0) -- The idle Wildcats move up a spot and can earn some national respect by beating Michigan State on Saturday at Ryan Field. Northwestern often struggles in highly anticipated games, but the team has a new defensive identity and has had two weeks to prepare for a Michigan State team it should have beaten the last three seasons (NU won twice).
5. Illinois (3-2, 1-1) -- Juice Williams' historic performance at Michigan Stadium and a defensive resurgence following a shaky start boosts Illinois in the rankings. The Illini need Missouri and Penn State to keep winning and to start capitalizing on a favorable upcoming schedule (three of the next four at home).
6. Wisconsin (3-2, 0-2) -- A spirited effort came up short against Ohio State, and the Badgers certainly weren't helped by Illinois exposing a Michigan team that rallied past them on Sept. 27. This is still a solid team, but questions at quarterback and with the running back rotation -- more John Clay, please -- leave Wisconsin staring at an 0-3 start to Big Ten play.
7. Minnesota (5-1, 1-1) -- There's a strong argument that the Gophers are the Big Ten's biggest surprise this season. They're still searching for a true signature victory, but to be a win away from bowl eligibility following a 1-11 season is a tremendous accomplishment for second-year coach Tim Brewster. The competition picks up in the coming weeks, but Minnesota is getting it done.
8. Iowa (3-2, 0-2) -- In most cases, football rewards a team that can rush the ball and stop the run, but Iowa hasn't caught many breaks this season. The Hawkeyes have dropped three consecutive games by a combined nine points. They have a great running back in Shonn Greene and a solid defense, but they just don't know how to finish.
9. Michigan (2-3, 1-1) -- The Wolverines can put together a solid quarter or half, but their warts usually show up during the course of a 60-minute game. The offense went to sleep against Illinois after scoring 14 first-quarter points. More alarming was the inability of the defense to contain Williams and Arrelious Benn. The result is a two-spot drop.
10. Purdue (2-3, 0-1) -- The Boilers executed a solid plan against No. 6 Penn State, controlling the clock and making key defensive stops. But struggles in the kicking game and by senior quarterback Curtis Painter left Purdue with little to show for its efforts. Things don't get much easier for the Boilers the next two weeks with trips to Ohio State and Northwestern.
11. Indiana (2-3, 0-2) -- It's October, and Indiana's only wins have come against Murray State and Western Kentucky. The Hoosiers' defense seemed to pick it up at Minnesota, but the offense stalled. Getting both units to excel at the same time will be key to getting out of the basement. This week's home game against struggling Iowa will be critical.