The stadiums are all great. The atmosphere just changes based on the year and the caliber of the team playing there. There are redeeming factors about all of them. Yeah, Illinois fans are pretty apathetic right now and yeah, they absolutely botched what was a stunning piece of architecture when they redid it, but Red Grange played there. Nebraska's stadium has the charm of a Wal-Mart, but it's hard to discount the amount of history that place has seen. Northwestern's stadium is great, it has a loveable loser charm about it and it's got mass transit close and a great view of the Lake.
All of college football is like that. There's just something magical about it - the whole sport. The stadiums aren't disposable like what they've done with the NFL and there is so much history at pretty much all of them and even if it is like that little shitbox in Ames, even the people who go to games there can rehash all the great moments, like that one time they almost beat Iowa and that other time when they almost beat Nebraska and that other time when they did beat Oklahoma State and kept them out of the natty. They are shrines to our country's excesses - we are so blessed that we live in a country where colleges have the money to build stadia with tens of thousands of seats, most of which get used 7 times a year. It doesn't exist anywhere else in the world.
And it doesn't matter where you go so long as you aren't acting like a pompous jackass wearing an opposing team colors (particularly an in-state rival's) you can roll in a total stranger and make fast friends with a dozen folks crushing beers and grilling brats on a Saturday morning. Sure, there are some asswipes in any crowd that size, but by and large, coast to coast, there ain't anything better than college football or NASCAR tailgating in terms of the friendliness of the average fans. And outside of college football and NASCAR, great tailgating really doesn't exist. The NFL tailgating game is soft compared to NCAA and there are waaaaay too many "NFL is serious business" jackasses who have room temperature IQs who will fight or assault you. Cowboys fans, Eagles fans, Bears fans. I wouldn't want to tailgate around any of those jackasses. Maybe Buffalo fans would be okay, but that's it.