As your going with Night Elf I would say your best bet would be Warrior.
If you don't want to be a tank (the bait taking all the damage) then a Rogue is good as you do nothing but Damage.
Druid is good at everything, but master of none, so you can heal, tank and damage, but your not as good as a warrior, rogue or preist at any.
That just leaves Preist (I think), which is great at healing and if you go shadow spec, is awesome at damage. Shadow Preists aren't welcome in end game Raids though as they are required to heal.
I've only played a Paladin through to 60 so can't really comment on all of them, but I will say that as a Support Class (Druid, Paladin, Shaman) it's a great class during the Solo parts of the game, but it's alittle empty in the Player v Player elements. I still love my Paladin but I wish i'd picked a Warrior (I'm lvling one now).