I know this thread has been done (to death) before, but I'll play:
US Cellular
Wrigley
Comiskey Park (RIP)
Also went to Olympic Stadium in Montreal, but not for a baseball game.
Also, on road trips to California and Canada and the East Coast, have driven by Jack Murphy, Dodger Stadium, Anaheim Stadium, Candlestick Park, Oakland Coliseum, Exhibition Stadium, Old Yankee Stadium and Fenway.