I'm best at solider, and my favs are Solly, Scout, Medic in that order.
It's very rare for me to play any other class. (Other than sniper when a good one gets on the other team and keeps sniping me as I try to get to the base because I'm too lazy to take the long route. Especially when I'm playing as solly because its takes entirely to long to get there :P)
EDIT: Dang Geo, me and you post at like the same time every time we post lol