Most: his vulnerability that isn't hidden as well as he'd like for it to be. His secret wish to be a hero. His sense of humor. And of course the obvious shallow stuff -- the HAIR! the EYES! the DIMPLES! the MUSCLES! the HANDS! and y'know, the beard and the back dimples and the feet and everywhere else in between.

Least: that's easy. The way he behaved toward Kate in the last two seasons. No WAY would the Sawyer *I* know let her treat him like a doormat, and not only let her do it without a word, but keep coming back for more. PFFFFTTTT!!!