I am not sure which stadium produced the most and have been unsuccessful in finding the answer online, but I do know Yankee Stadium was leading the pace most of the season and completed the 2009 regular season with 237.
The new Yankee stadium
in 2009 New Yankee stadium
citi field 288
Wrigley Field (1961 home of the AL Los Angeles Angels) 248
San Fransisco '49ers