4: AT&T Park (San Francisco Giants)
This ballpark is just beautiful. From the Coke bottle (product placement!) and glove beyond the seats in left, the cars in the left field wall, and McCovey Cove in right field, AT&T Park certainly is a unique ballpark.
While it opened in 2000, it is already on its third different name. It has seen a few no-hitters and even a perfect game, as well as Barry Bonds breaking the home run record here. For only being opened for 15 years, it has seen a lot of baseball history. The Giants have also won the World Series three times since leaving Candlestick Park.