Well, both of them fought for black people's rights but in kinda different ways. I think Malcolm X was a bit fanatical with his "black Islam" and ideology. I mean it was something really different than King's - he wanted racial segregation, said white people were evil, but even then he had his believers.
I was wondering why they had so different beliefs, maybe because they grew up in different enviroments.. King was born and lived in quite good conditions, Malcolm came from rather poor family and atmosphere of fear and anger..
Now, when black ppl mosty don't suffer like they used to in 60's, I'm more with King, because he showed that you don't need to bring violence and terror to achieve your purpose..