As a tank, Archers. They prefer to DoT everything before I get AoE aggro, and then run away with mobs rather than getting it to me. If I mark something with a "1", attack the "1" before changing targets darn it >:

As a healer... I'm pretty cocky lol. If the tank is moving REALLY slow and waiting for 10 seconds between every pull, I'll just pull and self-heal/tank if I think I can handle it. I hate when tanks AFK all the time. If you cant play, stop grouping until you can.