Most Helpful Girl
This is a hard one for me because there are always exceptions to the rules.
While traditionally you need to be attracted to someone to have any biological reactions (racing heart, flushed face, etc.), there is always the loophole of being friends. I've had a few guy friends who weren't traditionally "handsome" (they weren't ugly, per se, but not the kind of guys that make you turn your head as they pass you) and it was there personalities that drew me in. I'm all about sense of humour and in the end if I'm attracted to a guy's personality I will find even the most minute detail to help me find him physically attractive. If he's funny, it doesn't take long before I watch as he passes too.