Who should i use as tank

Ops! I mean:

You can NOT just mash a button and be a good warrior tank.

I have a few buttons for my warrior tank, but it's mostly just mashing the "everybody do something" button. My DK and pally both have a similar number of buttons. I miss the pally buffs when I'm playing my warrior, but they feel equally as effective (mid-level Northrend, 74-76). Tanking is tanking. :)

Druid if You already have a pally.

Paladin or Druid imo. Both bring group buffs and utility. Both can dual-spec to other interesting roles.