OK, I went to my first game in the mid 70's, but I was a kid going with my dad. The drive to Iowa city, if you'd asked me then, was an all day drive (even though the math obviously doesn't add up).
I went to all but three of those games. '81 I was a senior in high school...simply wasn't an option. In '85 I had taken a hiatus from college and, working full time at a sub shop, I could not afford a ticket to any game much less the Michigan game at over $300.
The others were all memorable....some thoughts on each:
Iowa-Wisc 2004 -
First, I had wisconsin fans in the row in front of me and my brother in law (a wisconsin alum) sitting with us. Before the game, the fans in front of us asked who to watch. I remember saying "You'll hear matt roth's name a lot". He freakin' ate it up at that game. The other was that my brother and I bought a foam cheese tie for my brother in law and, for some reason, started taking a bite out of it every time Iowa scored. It was a nub at the end of the game. People asked about the last time the fans just stuck around after the game ended, this was one. Another, earlier, was against Illinois and I was in the student section. We stood and chanted "Defense" for 10 minutes after a huge defensive stop to win (can't remember the year).
Penn State '08 (just those words bring a smile to my face)
I went with my brother. I had a feeling about this game after friends were saying we had no chance. Many were saying we were the best 4 loss team in the country at that point and I was one. The year I first saw a Hitler rant. Cold and windy, I was dressed for it with many layers and my Hawkeye dreadlocks hat. Dude behind me kept grabbing the dreads for luck. Had a blast and we partied until 4:30 am that night drinking cognac and smoking cigars in my garage. I was still hungover on Tuesday....but it was worth it.
Iowa-Indiana '09
Fun game. This is the one that would not make the list for me. I'd rank both MSU in '10 (total beatdown and the sash-hyde pic/lateral was something you just don't see very often) and Wisc '08 above it. My brother and I went from WTF to holy crap in one quarter against Indiana. Sitting in the 70th row, I was confused as when Sash got the ping pong interception. Indiana fans were sure the fix was on with a TD called back on replay (IIRC).
Iowa-Pitt '15
OK, this game obviously didn't have the conference or even bowl implications at the time. That being said, as Hlas noted, there were a number of factors that fed it. First, the fans were hungry...I mean starving...for some excitement. I know allergies hit me hard when Brett was introduced and I was far from the minority. Too many memories of him, Sash welling up, along with the power of watching Angerer and Doyle helping and literally coaching him through it...OMG (those three letters are used lightly these days but in this case I mean it).
Throw in the 10 minute I-O-W-A chant, the dramatic finish and people simply standing there screaming after the game ended....this is a game I will always remember even though the implications aren't there (for now I hope). How cool would it be if we get to the end of the season and think about how crucial this win is (like the double blocked FG vs UNI)?
A few honorable mentions: (and I'm not good at years)
The beat down of Michigan with all the failed rugby punts. My brother laughed and screamed like crazy at that game.
The ass whooping of tOSU in....'03? After decades of hating Ohio State, that game was a catharsis. I had a blast.
Wisc in '08. Watching Shonn Greene run over them like a steamroller was a blast.
Michigan '09 - That was probably the most "electric" I've seen Kinnick (except maybe when we beat Wisc in '03...but this the whole freakin' game). You could have walked on the energy that night. Then the Moeaki TD's down the seam were a thing of beauty. Just a really fun game.