I've been to every one of them except PSU. I'll probably go there next year. Oh, I also haven't been to the new Minny stadium, and I'll be there this year. I've been to some of them several times.
OSU is everything that people say it is. It's a shrine to college football. Really loud. I can see why teams go there to lose.
Cramp Randall is, in my opinion, not as high on the list as some might have it. It's a great venue, but depending on the time of the game, many fans are either quiet or not even there when the game starts. The stadium has some good seats, and some seats that are barely in Dane County. Having said that, I live in Madison, and I love seeing Iowa win in that place. Last year was awesome.
Ross Ade is okay. Kind of a neat old stadium. The "boiler up" chant gets really, really old. Particularly when Jake C is your QB.
Northwestern's a fun trip, because so many hawks are there. I'll be there this year. I used to live in Chicago, so I'd just take the "L" up to the game. That was really nice. NO driving.
Indiana is fairly lame but a person can make a nice trip out of it. Tickets are pretty easy. Haven't been there since they did the new addition in the end zone. They needed to add capacity to an empty stadium ?
Michigan is just what folks say it is. It's not that loud. It's a nice place to visit, but it doesn't "rock."
MSU's SPartan Stadium, I think, is good. The seats are pretty good. It's got at least 75k in capacity, and some of the better Iowa games I've ever seen have been there. It's a good trip.
I've never been impressed when I've gone to Illinois games in Champaign...for many reasons.