When I got the game, I went straight into Practice and starting fiddling with the female characters because I generally always play a female character in fighting games. Kitana, Orchid, etc.
I started off with Raven, then Hawkgirl, then Harley, then Wonder Woman, then Frost and finally Catwoman. Catwoman was my main about 20 minutes after fiddling around with her. I'm pretty good about being a character loyalist and had no desire to learn another character. After a few months of playing, I started to get bored with her and entered a character crisis. I was ready to stop playing the game and go back to playing MK. Well, VxG had just recently ended and I watched the Grand Finals and saw PL blow up Chris G with Doomsday. I was immediately intrigued with how Doomsday played and picked him up.
I never thought I would play Doomsday because I hated fighting him when playing Ranked/Player Matches. Well...here I am, still playing Doomsday and enjoying the game a hell of a lot more than I did when playing Catwoman.