In ranking baseball's ballparks, everyone has a preference. No, I have not seen a game at every stadium, so yes, I will have biases for, or against, stadiums in which I've had certain experiences.
Also, I'm a baseball purist, so I'd rather not see the ballpark have an impact on the game. Stadiums like PETCO Park, Citi Field, the Oakland Coliseum (O.co) and Target Field get bumped down because of their clear favor towards pitchers. Also, as a purist, ballparks like Fenway, Busch and Wrigley got a slight edge for their history.
Part of the beauty of baseball is the uniqueness of each game. Every umpire has a slightly different strike zone. Every crowd has a different approach. And every ballpark is an entirely new experience.
One last thing that went into these rankings is considering the cost of seeing a game live, including tickets, food and transportation, what are the odds the fan will get to see the home team win?
That wasn't the most important factor, but it did go into the rankings.