I "root" for a lot of teams based on personalities, styles of play and my connections to the area...however there are very few teams of which I'm a fan. There's a huge difference to me.
NFL
Packers - Obviously, they come first above all my other teams, its really the only team in the league I follow. Born and raised its like a religion...don't miss a game unless I absolutely have to...
Colts - have family around Muncie and I like Peyton
Bears* - I don't "root" for them, in fact I hate them but I have the utmost respect for them as a team. If the Packers did not exist, I'd be a Bears fan.
CFB
Badgers
Gamecocks - Used to live in the Columbia area
Boilermakers - My Grandfather's the oldest living alum
Huskers - before the realignment, still a little bit when it doesn't hurt the Badgers
K-State - I root for them occasionally just because I live right down the street from them but I'm no big fan, just a passing interest
Michigan - root for them in the Game because I hate OSU, really liked the team when they had Hart and Henne...not so much now
LSU, Bama and UF (under Meyer)...simply because of the coaches
Troy and Fresno State- My Mid-Major teams, I just like how they're not afraid to play tough teams
Georgia Tech - Lived in Georgia for way too long, got sick of UGA fans and I'm digging the Option
Army- Only for the Army-Navy game, not a big fan of the Academy...reminds me of the Army version of Hogwarts
Tennessee - Dated a girl from Knoxville and they kind of grew on me and I love the state, I'd like to retire there...its just beautiful
NHL
Red Wings - I have no real reason to like them but they were good when I started watching and they've grown on me
MLB
Brewers
Braves
Cardinals - I don't really "root" for them but I used to always watch them as a kid because my Grandfather was a fan so I keep up with them
NBA
Don't care that much, not a Bucks fan though, kind of prefer the Bulls but don't really care
College Basketball
Wisconsin
UNC - No reason here, I just really, really hate Duke
Michigan State-As long as it doesn't hurt UW, I like Izzo...
Teams I hate
NFL
Steelers - Tons of respect though
Vikings - I hate the Bears but I love our rivalry and their history, if the franchise was in danger I'd be pissed and want to save them, however if tomorrow the Vikings were to cease to exist I wouldn't give a sh#t. f#*k Minnesota
Patriots
Cowboys
CFB
Notre Dame
Ohio State
Minnesota
UGA
Clemson...ok most teams from the ACC
Boise
TCU
USC...and most of the Pac-12
Auburn
Arkansas
Texas A&M...just because of the Corps, they think they're hot sh#t because of their boots
Indiana
NHL
Stars
Avalanche
MLB
Yankees
Mets
Red Sox
Twins
Cubs
College Basketball
Indiana
Duke
OSU