As the others have said, defintely play whatever class you're having fun with. The one thing that has always bugged me is when people complain that you can't play a certain race/class combination because they won't have the best stats and are therefore pointless to play. I purposely pick a class/race combination that you don't see as often (Mithra WHM) for the simple fact that I hate having the same character as everyone else(Taru WHM).