Bard
I can do everything, and a good bard is a huge
force multiplier to any EQ group. I've personally seen the difference between a good and bad bard in the group, both as a tank (paladin) and the bard. More than any other class, watching a great one is like listening to a well orchestrated symphony while watching a bad one makes me want to rip my ears off to end the cacophony (puns intended).
What really got me into the bard class was one time tanking in Bastion of Thunder on my paladin with a guild group of cleric, mage, bard, wizard, and one other. The mage had the Call of the Archmage spell, the bard was an amazing puller and spot-on with the CC when COTAM broke and the bard just chainpulled our wing; it was like a hot knife through butter all night long.