Here are three lists. One list is for all the ballparks I have attended, in consecutive order, with first date of visit, if I've found the date. I'll be checking ticket stubs and box scores until they're all listed. I may also link to a box score. Another list is for all the ballparks replaced during my adulthood that I never visited. The last list is for current ballparks I have not yet attended.
Ballparks I have visited for a major league game:
Oakland Coliseum, Oakland - July 11, 1970 [box score]
Candlestick Park, San Francisco - August 3, 1974** [box score]
Anaheim Stadium, Anaheim - August 17, 1985 [box score]
Jack Murphy Stadium - August 18, 1985 - DH - [box score 1] [box score 2]
Kingdome, Seattle - April 18, 1986 [box score]
County Stadium, Milwaukee - May 5, 1986 [box score]
Wrigley Field, Chicago - May 6, 1986 (day) [box score]
Old Comiskey Park, Chicago - May 6, 1986 (night) [box score]
Dodger Stadium, Los Angeles - 1986 [box score]
Yankee Stadium, New York - Sept. 29, 1986 [box score]
Olympic Stadium, Montreal - Sept. 30, 1986 [box score]
Royals Stadium, Kansas City - June 15, 1987 [box score]
Busch Stadium II, St. Louis - June 17, 1987 [box score]
Mile High Stadium, Denver - July 30, 1993 [box score]
Pro Player Stadium, Miami - May 26, 1998 [box score]
Pac Bell Park, San Francisco - April 11, 2000 [box score]
Bank One Ballpark, Phoenix - August 30, 2001 [box score]
Petco Park, San Diego - 2004 [box score]
**My best guess at this game. It was a day game at Candlestick vs. Atlanta and Hank Aaron didn't play.
Ballparks I missed out on:
Exhibition Stadium, Toronto
Memorial Stadium, Baltimore
Municipal Stadium, Cleveland
Arlington Stadium, Arlington, TX
Atlanta-Fulton County Stadium, Atlanta
Tiger Stadium, Detroit
Astrodome, Houston
Three Rivers Stadium, Pittsburgh
Riverfront Stadium, Cincinnati
Veterans Stadium, Philadelphia
DC Stadium (RFK Stadium), Washington, DC
Shea Stadium, New York
Metrodome, Minneapolis
Ballparks I have yet to visit:
Fanway Park, Boston
Skydome (Rogers Center), Toronto
New Comiskey Park/US Cellular Field, Chicago
Camden Yards, Baltimore
Jacobs Field/Progressive Field, Cleveland
The Ballpark/Rangers Ballpark, Arlington, TX
Coors Field, Denver
Turner Field, Atlanta
Tropicana Field, St. Petersburg, FL
Safeco Field, Seattle
Comerica Park, Detroit
Minute Maid Park, Houston
PNC Park, Pittsburgh
Miller Park, Milwaukee
Great American Ball Park, Cincinnati
Citizens Bank Park, Philadelphia
New Busch Stadium, St. Louis
Nationals Park, Washington, DC
New Yankee Stadium, New York
Citi Field, New York
Target Field, Minneapolis
[Update:] Marlins Park, Miami
