I didn't really main anyone.. I almost always picked random.. I liked to change things up constantly.
But I'm really looking forward to Playing Greninja.
Super Smash bros. obviously.
Dragon Age: Inquisition seems promising.
..and Everquest Next I suppose. but that is mostly hype atm.. But they do seem to take a new spin on the MMO genre.
Oh and Heroes of the Storm seems a lot of fun.