I liked Wrigley, The Jake and absolutely fell in love with PNC in PIttsburgh -- hard to top that one. Our new park here (GAB in Cincy) is cool too and a very good time. A perfect blend of history and modern, I think.
Busch was kind of neutral, I thought. Not a bad experience but pretty blah, all in all (the ballpark, not the team LOL). I liked Fenway, I loved the history and the atmosphere of it but it could benfit from some renovation and updates. I'd hate to see it torn down though -- just improve it. Those bathrooms ought to be closed down by the health board.
PacBell looks cool, love to go out there.
Oh, I think my least favorite of all time has been Shea. What a boring, bland, dump.