Joker, maybe. I mean as someone else said, he is basically king of one task and otherwise just known for his wit. Sounds almost TOO MUCH like me. *Shudders*
If not Joker...maybe the Courier from New Vegas. I mean if nothing else it seems like I have about that much luck - get shot in the head over a trinket because someone decided it was above my pay grade to be told what I was actually carrying until I messed it up.
Now, if I could PICK one, yet still staying within reason...Nameless MechWarrior Pilot C, I guess? Seems like a job that in an alternate future I'd love to have. I've never been one for the military IRL (keep trying to get a boot camp waver to join the cyberwar division but they won't agree to it... geniuses) but somehow I think piloting a massive fighting robot has much more to do with technical skills and tactics and much less to do with how much you can bench press. I doubt I'd have much of a kill record, but I do think I could survive that.
Alternatively, maybe Van Brugen from DXHR. The guy with no armor and a pistol donated by the real hero who still somehow manages to make it out of the fully surrounded apartment complex unscathed. I'd also give Jensen the money. Just seems like a fair trade - 4k credits for a pistol and my life. Sad thing is, when you think about it, Van Brugen is really more adept at stealth than Adam. But he clearly has a lack of nerve. So yeah...sounds like me.
I can think of a few more but those seem apt enough.