For me, the guy at Marvel who fills that bill is Deadpool.
I was never a Rob Liefeld fan, never got into the New Mutants or X-Force, so that entire line of characters has largely gone by the wayside in my brain. I know Deadpool is popular, but he's just a gun-totin' blowhard to me (by the way -- check out the left forearm in the image to the left... I say "Image be damned!!"). He just doesn't resonate with me. I wouldn't say I hate him -- I'd just say he doesn't register anytime on my Care-o-Meter.
And, over at the Distinguished Competition, it has to be Firestorm. I believe he came 'round during the period I was out of comics (early 1980's -- I could be off a bit). So when I got back in, I saw his books on the spinner racks, saw him in the JLA, but just never found the character, the look, or the backstory attractive. I mean, again, I don't hate on the guy -- just don't really have any involvement with him, no attachment.
So who's yours?