I'm honestly going with Maggot here. The kid can grow maggots out of his skin. That kinda stuff belongs in a crappy horror movie, not a comic book.
The best for me is Beast. I absolutely love Beast. The idea of a furry blue guy who can fight with the best of them who also knows what the 30,000th digit of Pi is is just cool to me. And after reading the recent comic run of Astonishing X-Men, I have to say that I also really like Kitty Pryde, who's never been a favorite character of mine. I guess it took the right writer.
In other news, I think it's about time we had the original 90s cartoon released on season set DVDs!