DPS first chance from me, if they haven't screwed up too badly. They're overlooked a lot and things wouldn't be managable without them, holy trinity style.
Tanks/Healers joint second. I'm not going to commend a tank for grabbing an add that's coming at me though, that's like me asking for a commendation every time i heal up a bit of damage.

Healers, i'm actually more leaning to i usually don't give them to healers (i'm one myself), unless they were exceptional. We get them thrown at us from practically everything else.