This is a big question, and deserves a size-relative answer.
My favourite magicians would have to differ over certain area's-
In terms of pure creativity, I love the works of Jay Sankey, Paul Harris (though i'm JUST starting to lose a LITTLE faith), Mike Skutt, Wayne Houchin, Marc Oberon, David Forrest, David Harkey, Mathieu Bich, and greg Wilson.
In terms of performing ability, I love to watch Greg Wilson (so cool, without even trying), Apollo Robbins (the term 'hardcore' is so apt with this guy), Derren Brown (just amazing style-the only magician my girlfriend will sit and watch with me), Banachek (for tackling mentalism without being super serious constantly),Pete Firman (very funny guy), David Acer (funny and excellent chops!), Homer Liwag (just...those coins are just vanishing in his hands!) and various others that aren't coming immediately to mind.
Guy's i appreciate for the technical skills they posess, Homer L again, Gary Kurtz, Ray Kosby, Chris Kenner, Apollo again, Shoot Ogawa, Troy Hooser, Justin Miller, Aaron Fisher, The Bucks, Greg Wilson again, Chad Long, and the list could go on...
basically, i could MAYBE choose a 'greatest hits' collection of creators, performers, and writers, but i would find it impossible to choose one absolute favourite.
C!