The Daily Grind: Tank, DPS, Healer, or other?

The small group gameplay in many of today's MMORPGs is about the interplay of several archetypes that each offer something different to the dynamic -- tanks absorb damage so weaker classes don't have to, DPS classes dish out massive damage in short amounts of time, healers reverse or prevent damage done to party members altogether, and then there are a myriad of other classes that fill various other roles like crowd control.

Seems a lot of folks fall comfortably into one role or another -- some even stick to just one through multiple games, always playing healers, for example. Do you have a strong preference for one particular group role, or do you try to vary your play experience? In either case, which role is most comfortable for you, and why? We're always interested to learn more about the psychology behind these games, so we're eager to see what you've got!