I don't know if he ever had his own comic but I love the character of Apocalypse. Incredibly powerful, knows the future, knows he has to destroy it, to lazy to do it himself...
Gambit is the man as well as Wolverine, actually I think the x-men as a whole are terrific with the exception of Cyclops whinny ass.
I have to agree that the relationship between Xavier and Magneto is amazing and even the movies are slightly picking up on that.