Mine would be either “Martyr” or “Exhibitionist”.
Black Sheep. 
I even have the stuffed animal to prove it. For Easter a couple of years ago, my mom gave everyone a stuffed animal. Everyone else got ducks. I got a black sheep.
My wife: Beer Wench
Me: Drunk
:wally
Gee, it took me so long to actually log in that I forgot what I was answering… :o
Troglodyte… yup, that’s it, troglodyte 
I’d be the uncomfortable with any emotion so cracks jokes member of the family. Actually, me and one of my brothers are typical middle children…we sort of learned to do our own thing and accept not standing out, while the oldest is the hero and the youngest is the black sheep and therefore get all the attention.
Hmm, you must have a different family dynamic than I do, because I, as the youngest child, am the Emot-o-phobic Family Jester, while my middle-child sister is the black sheep (in HER estimation, anyway).
But you’re right… I do get all the attention (it’s the exhibitionism, you know). 
I’m the Far Away Boy. Kinda hard to explain, but I’m the one who tends to be a bit away from everyone else. Being the younger child, and unable to get away from stuff, I’m dragged down, no one else in my family is.
Well, I think I have already answered THAT elsewhere today . . .
Memory.
My sister called the other day to ask about the origin of several scars on her hand. My brother did it when she was two. So that would be 1969, springtime. We were loading up into the Volkwagon Campmobile going on a trip to Port Aransas, Texas. He pulled a butter knive out of her clenched hand…
I say every family needs one of you. But what do you do after Thanksgiving dinner…? Fall asleep in front of the tube with your hand down your pants, or continue to slave away in the kitchen, cleaning up the mess?
Stubborn Mule
My sisters may have bratty moments, but my parents hardly blink after the hell I put them through when I was little.
Historian. Care giver.
Gobshite
Interpreter. Being the only one in my family who can both sign fluently and hear, I’m the one who interprets between the deaf members of the family and the hearing ones since none of the rest of the family ever really bothered to learn to communicate. They can manage conversations without me but they tend to get a little… confused. I’ve overheard my aunt answering a question from my dad about the state of affairs in the middle east with the reply “Yes, you do like skiing don’t you?” So generally I get to spend all day interpreting at family events.
Of course, there’s scope for me to simply make up what the other person said. It’s been known to happen. hehe.
Cook. All family holidays, I’m in the kitchen. I usually don’t mind as I’m pretty happy with doing it (and if I didn’t do it, they’d be ordering deli trays and cracking open bins of potato salad–even on Christmas).
Health Nut
It began about 5 years ago when I started to lose weight. Then I went to work for Weight Watchers. Then I started running. Then I started running marathons.
The above may or may not have anything to do with that.
I have a pretty lazy and somewhat heavy family. So my success (to date, knock on wood) is somewhat noteworthy.
SHOOT! Just realized I forgot to start this week’s Dieting Dopers thread…
3rd child. duh.
"I am my family’s Official Family …
Fuck-Up"
Thanks for playing.
Tech support
Having trouble with your computer/VCR/camcorder/stereo/TV/cell phone/whatever? I’m the one everyone calls.
My folks, my siblings, my wife’s folks and siblings, all call me when a roof leaks or fuse blows (that actually happened!) or computer crashes or boyfriend leaves or proposes. I dispense advice, sweat, and tools.
I kind of like it, it makes me feel like I am needed!