Who's your favorite mutant (marvel) character and why?

Actually, Deadpool IS a mutant. He had mutant powers before the Weapon X program. His healing ability he has had for pineappleing ever.

Actually no, lol. He got his healing powers from Weapon X.
I just checked some sources to double-check, all confirmed that he got his powers from Weapon X, he is not a mutant.

http://x-men.wikia.com/wiki/Deadpool = "After Weapon X cured his terminal cancer by implementing a regenerative "healing factor" extracted from Wolverine, Deadpool is left disfigured and mentally unstable. "

http://en.wikipedia.org/wiki/Deadpool = "Deadpool's primary power is an accelerated healing factor, depicted by various artists and writers with varying levels of efficiency. Artificially endowed by the Weapon X program, this enables him to regenerate any destroyed tissues or organs at a super-human rate as well as making him immune to known diseases and infections."

He is like spider-man a human mutate.