the stadium express has been discontinued your best bet would be to stay downtown take a cab or depending on where you are staying check with the hotel to see if they have any baseball packages some hotels offer tickets shuttle to from the game your other option would be to stay at a the Holiday Inn located across the street walk to the stadium
You could stay by the ball park but there wouldnt be as much to do. Downtown has most of the nightlife, and there are busses there that take you places like the Plaza, Westport, etc. I would suggest that you take a taxi to and from the games.