What do we mean by good stadium? I have been to many stadiums world wide, some just tours while on holiday and some while supporting England. The San siro looks impressive, but once your inside you realize it has many faults, for example many seats have next to no view of the **** pitch!!! And it's a very untidy stadium, they don't maintain it very well at all!
Camp nou is very impressive, but again it was just in a horrid condition when I did a tour in 2007, it needs a decent refurbishment badly.
Did a Bernabau tour in 2008 while on holiday in spain and honest to god we found human s**t and p*ss in the hall ways it was so wrong. It's a very very nice stadium but that image will always ruin it for me lol
Old Trafford and Wembley are my top stadiums, they tick all the boxes, state of the art, very well looked after, decent size and both give an amazing experience.