Bayonetta because, although it sounds silly, the character inspired me to get in shape and enhance my character. By that I mean that I usually let things that people say slide (even if it's lies or something) and don't really question them. I don't have the patience to entertain people who lie or are bullshitters so, thanks to Bayonetta, I've developed a much more "no-nonsense" approach to people. Not to say that I've changed because of her, because I could always detect bullshit, but never called it out. Now, I don't tend to hold back (although I'm not saying I'm a ***** to everyone who says something I disagree with, not that at all!), I'm becoming much more comfortable with being the openly sexual person that I've always been (without worrying about how I'm being perceived) and she really made me realise that glasses ARE sexy!
I think you probably meant which character was so amazingly awesome that you cared for but...you got more than you bargained for, OP!
Great topic, I can see some interesting responses arising.