I am sorry, but a stadium list is not complete without discussion on PNC park. This stadium's design is a true masterpiece. The way it blends the game in with the city and rivers is great. I only visited 3 stadiums so I may be ignorant on which on is the best. However, having a discussion about baseball stadiums and not mentioning PNC is ludicrous.
ESPN thinks it rates the best:
http://espn.go.com/page2/s/ballparks/pncpark.html