As far as stadiums I have been to, Qwest Field in Seattle was great. I have been to Metallica there, but last month, I saw Real Madrid there and it was awesome. You're watching a game, but in the background, you can see the planes coming into Sea-Tac to land.
BC Place is the biggest hole I have ever seen.
As far as places I would like to go, hulkrogan above had it right on, the estadio du luz is awesome. If you don't wanna go based on those pics above, there is something wrong with you. Another one I would love to see is also in Portugal is in Braga and was made for the Euro 2004 tourney(tear...damn you Greece)........anyways, the architechts carved part of a mountain to make this stadium. Here's a pic below, not the best one, but it's still pretty sweet.
