#1 is Michigan State. The entire SU football staff under Biggie Munn moved there in 1947 to build up that program and SU grad Duffy Daughterty took over for Munn and they had some great years there in the 50's and 60's as a perennial national power. In my mind I've always had a "best ball" scenario between us and them: what if you combined the schools success year by year over the decades since. it would be quite a program. The Spartans also fit a couple of other profiles to gain my sympathies. They were good when we were good in the 50's and 60's, then faded and have been ntrying to come back to that level, with occassional but not consistent success ever since. They have also been sort of the junior partner in a rivalry wiht Michigan, (although they've done well the last few years), the way we became the junior partner in the Penn State rivalry.
Other "junior partners" I tend to root for: Georgia Tech vs. Gerogia, Auburn vs. Alabama, Arkansas, (where I have kinfolk), vs. Texas from the old SWC days, Nebraska vs. Oklahoma, (Nebraska only won when they were clealry better), UCLA vs. USC.
In the "they were good when we were good" category would be Georgia Tech, Mississippi, the western half of the Big Ten, the private schools from old SWC and the northern schools of Pac 8/10/12.
I also tend to pull for Mountain area teams, which traditionally have been under-rated and left out of things. I liked Arizona State when they were in the WAC, Wyoming, Utah, now Boise State. I never warmed to BYU for some reason.
Uniforms: I always liked UCLA and LSU, (when we copied them it looked OK but just wasn't us). I like Tennessee orange and Carolina blue. I liked it when UCLA and Tennessse would wear their colored jerseys at home and on the road because it was such a light color. I wish more teams would wear colored jerseys against each other when there is a contrast. I do want a contrast in the jersies vs. the pants and helmet. All one color is a bit much.
If I like the coach, I will root for his team. I liked Bud Wilkinson but didn't like Barry Switzer. I liked Ara Parseghian but didn't like Gary Faust or Lou Holtz. I started out like Joe Paterno but that faded badly ver the years. I started out not liking Bear Bryant but gained respect for him over the years.
And I always rooted for Eastern or Big East teams against intersectional or non-conference opposition. I rooted for Ithaca when they were playing for national titles, (when will this Mount Union-Whitewater thing end?) I'll root for Colgate on their level and would do so for Cornell if they were any good. I've always rooted for Delaware and UMASS for some reason. They were the top small college teams in the East back in the 60's when I grew up. Coach Mac later coached UMASS and my cousin was professor at Delaware for years. I also developed a fondness for North Dakota State when I read a great article about them in SI back in the 60's and have followed them through their years of great success, including last year when they won the FCS title over Sam Houston State.
But I don't bleed their colors. I bleed Orange and would always root for SU against any of them.