Zevran. The guy comes off as a bit of a sleaze, and I think that turned a lot of people out (that plus there are plenty of homophobic idiots who felt threatened by him). But he's much deeper than he lets on. If you take the time to get to know him, you find he's a pretty broken person, and much of his personality is just a mask to keep others from getting too close. Whether you keep him as a friend or engage in a romance, his is definitely one of the most engaging and emotional storylines.