I've been to around 10 regular season Red Sox games, and 2 playoff games there. The first playoff game was Game 3 of the 2003 ALDS vs Oakland, where Trot Nixon hit a walk off homerun in the 11th inning to win it. The other playoff game was Game 7 of the 2007 ALCS where the Sox faced the Indians.
As for other MLB parks, I've been to
- Olympic Stadium in 2004 (Montreal Expos) last year they existed. They were always my second favorite team. They beat the Dodgers with a walk-off walk. Pretty cool.
- Turner Field in 2006 (Atlanta Braves) Great stadium, huge screen in centerfield, and I got Papelbon's autograph.
- Petco Park in 2007 (San Diego Padres) Beautiful stadium. Greg Maddux pitched and the weather was perfect (when is it not in San Diego.)
- Going to AT&T Park this summer, I'm really excited.
As for Minor Leagues, I usually go to 4 Lowell Spinners games a year (Boston Red Sox Single - A affiliate.) Their stadium is LeLacheur Park.