I vote for Wizard.
Druids are as said, a dime a dozen, you can't walk through a zone without tripping over one.
Druids as a secondary healers are pretty poor, a shaman could fill the roll 10x better with buffs and being able to assist in DPS without running out of mana, on top of having a larger variety of damage types against resistant mobs and a passive pet.
Druids as added DPS is again, poor, when compared to pretty much any other class besides a Cleric... (and a cleric with a manastone could probably out damage a druid in the long run.
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Wizards, while annoying to watch them sit there and suck XP, they come through in a clinch far better then a druid could, if theres an add that needs to die right now, wizards got that covered.
Druids solo, powerlevel and port for money... thats all the do, i actually hate to group druids cause i know 9/10 of them are just making druids to leech plat from porting and powerleveling and claim camps from classes that could actually use the drops.