Bayonetta easily. She's one of the most powerful characters in gaming period, she has a very strong and unique personality... and I really like her design (well, both of them).
But the thing I love the most about her... is the sweet irony behind the character. Someone who hasn't played any Bayonetta game might think that she's oversexualized without any ingame reason and that all those poses and horny scenes are to attract the male audience. But in reality... she does all of that and is all of that simply BECAUSE SHE CAN AND SHE WANTS TO. She enjoys teasing her angelic oponents with suggestive comments and postures before she absolutely obliterates them. It's like showing them who's the boss. The best part is that her enemies are usually angels that are inspired by christian religion. What are some of the things christianity hates the most? Let me see... witchcraft... empowered women... lust... Oh, look at that. Bayonetta is the embodiment of all the things her enemies despise. And she beats the crap out of them while making sure to scrub all of those qualities on their angelical faces.
I don't know... it's just precious irony to me. Truly love Bayonetta. Like Rodin would say: "BEAUTIFUL!"