Michael Jackson, U2, Tom Petty, Prince, and The Who have been my favorite halftimes to date. I haven't enjoyed any of the halftime shows since then other than Coldplay.
But I also watch the game. I'm not a big NFL fan but I watch it when the Colts are good. Unless the Colts are playing in the SB, I just enjoy getting to watch a game of two decent teams where I don't have a dog in the fight.