Well i as a tank do enjoy the following,

People that greet & talk to begin with.
DPS that dodge stuff, Don't pull stuff before everyone is ready(i usually let em die if i see the healer needs some MP >.>)
Healers that are good at their job as in, Pre-heal/buff and remove stuff.

And everyone else that shows patience to new people and actually spend 2 minutes explaining stuff instead of just running and throwing the new guy into the deep, Even when he's asking for a simple explanation of the mechanics.

Alot of people could learn from those people. Keep it up & Cheers!