You know what else makes a woman weak in the knees? A tragic back story (and the voice of Troy Baker).
Booker DeWitt is man with past mistakes and a never-ending guilt, leaving people with a desire to see him earn his retribution.
Maybe it's the fact that DeWitt has a personality (as opposed to the other BioShock protagonists); maybe it's because of his interactions with Elizabeth; maybe it's the clothes.
One things for sure, though: if you know how to handle a gun and you have a voice like Troy Baker, then you've got a place on this list (and in my heart).