I've not tried many of the classes. Don't like playing outside my main realm and have too many high-level duplicates to delete and try more.
That said, I'm really, really struggling to get back into shaman. She used to be my favourite main in WotLK but... The class just feels clunky in Cataclysm.
Also have a level 62ish rogue. Just.... Simply can't play her at all! I don't want to delete her because there's so many memories connected to her (was one of my very first characters) and roleplaying her is fantastic fun, but I simply don't understand the class and am always, always bottom of damage meters when I do try. I'm usually kicked from PuGs.
Desperately want to try priest/paladin... But no room!