Healer who wears cloth and sucks outside of groups! Screw clerics!
EDIT: But it's totally okay to still be awesome outside of groups or different from the norm. I still remember tanking the back of the Four Horsemen in Naxx as a Discipline Priest wearing PvP armor back in the day. Good times.
I like the idea of being a game-changer or a powerful force while still remaining very vulnerable. It's why I don't like creatures very much in Magic: The Gathering, why I like "small-ball" in baseball, why I like sharp positions in chess.
As a healer, I can't go anywhere without the group, but the group can't go anywhere without me. I can be the most important factor in a raid's success, but not everyone needs to realize that, or even notice it. I can salvage someone else's fatal mistake with lightning-quick judgment and action. Yet I can fail just as easily, if not more so. I could be the fatal mistake; in fact, I enjoy when I fuck up, because it makes things all the more interesting.
I like the idea of "clutch" to the point where my goal in such games is to be that guy that everyone wants to have their back in their most critical moment, but I don't need to be the best healer all the time. Who do I want people to want to have healing or making decisions when shit hits the fan? Me.
Tanks can only tank. If they make things interesting, they're just called a shitty tank, because the DPS has to cut back to avoid aggro. DPS can't make things interesting because they're just DPS. If they're not going all-out, they're kicked out. As a healer, no one keeps track, except maybe the tank. But the tank has got a job to do, and if he's still doing it, there's nothing wrong. So if I'm healing him just enough to keep him alive, I'm doing my job. That's what's different.
If I'm plaing a solo game, I still want to be easy to kill. Why? Because I'll make it so they still can't kill me. It'll always be a "critical moment," because any mistake could mean death.
In the same regards, I like taking the most difficult or even worst path to success, and succeeding with it. I'll run around in Call of Duty with a silenced bolt-action sniper rifle--my secondary weapon being a rocket launcher that can only shoot down aircraft and my grenades being smoke and flash--for the hell of it.