Choose any class but a warrior and shaman, especially if you intend to PVP.

Paladins are fun - there is a reason there are so many of them
DKs are fun - ditto
Druids are also very fun.

Warriors get taroh so much their backside permanently open bunga raya.

but look at the shamanz these days... 4 totem drop instantly without regarding situations and don't purge buffs or replace those totems that had been destroyed (oddly less and less people destroys totems...).

wtb some frostmourne horde shaman player i met during level 39...

and when some site said that taking a paladin down is like doing a quick raid with 3 phases...

Drop me a note and bring your warrior over to the PTS and show me then, oh mighty High Warlord.

lol, roll a dk if u have the choice, its still really OP. high survivability + high dps higher then pally but ocasionally equal to rogue (subject to arguement). i do ocasionally out dps a rogue. but i really crit alot about 23k the highest ever in HOR. dk is best in pulling casters with dg and works wonders in HOR. with strangulate. ohh and btw i have an 80 mage too. its really nice to play, pure damage low survivability. crit 18k with ab. but total damage for  arcane missiles can exceed 35k if u crit nonstop 5 times. =) im currently playing a pally, really high survivability, high dps but bad agaisnt casters =(