Zane from The Well of Ascension. Definitely Zane.
I'm usually not a sucker for the whole "insane and broken and need you to fix me" character, but Sanderson writes him with such flair that I can't help but fall in love with him.
As my favorite book would've put it, "You were so easy to spot, the [only] man with [any] fire behind his eyes."
There's a bittersweet edge to his story, you get the feeling that if his life had been a little different, he would have been a different man altogether.
Or maybe I'm just crazy.
Did I mention that I imagined him having dark skin, a shaved head and eye tattoos?
Yeah, definitely crazy.