Rob Iracane has a print-and-save article for you over at Big League Stew: “The top 10 brews available at MLB parks.”
Warning: he hates on Natty Boh and other local beers with a long history but with a bad taste. Which is exactly what he should do because we’re in this for the beer, not the nostalgia. But that sort of thing can be jarring to some, so I offer the warning. He makes an exception for Iron City in Pittsburgh. I’m not sure I agree with that exception, but he makes his case based on pragmatism, not some amorphous local flavor angle.
Overall it’s a pale ale-heavy list. That also makes sense because pale ale is the nectar of the gods, but I have a confession to make: when I’m at a ballgame, I tend to prefer something a tad thinner. Not watery -- indeed, I only go for the macrobrews if forced -- but I usually hit weekend day games when I go to major league parks, and summer ales and stuff like that tend to do better for me in the hot sun of a July afternoon.
Enjoy.