I've barely played spy at all, don't like it much. I've never liked spy though through all versions of TF, although it was pretty fun in FF since you could hijack the enemies turrets. I don't have a favorite class, but play soldier, engie, scout, medic, and pyro depending on my mood and the situation. I think scout or pyro is the most fun to play and medic is least fun, but the situation varies and sometimes being that bastard engie who set up a turret inside your base is a lot of fun. Every once in awhile I will go demo, and even more rarely sniper. I've never found either to be a lot of fun, probably because I suck at both. I loved sniper in FF, I'm sad the TF2 sniper is so crappy relative to that.