1) He has style - that doublebladed lightsaber is fantastic - I also like his wardrobe (he choose the right colour for his starship - black like my car!)
2) I like his dedication - even though he is dedicated to evil - he had purpose in mind and he spent his whole mind, body and soul in trying to realize his purpose. He was not halfhearted - like most people are these days - he threw himself in to sink or swim! I admire such commitment.
3) He was competant - he was far more skilled than either of his opponents, and if it weren't for Lucas he probably would have beaten Obi-Wan as well. I admire his considerable skill.
I think that we should try to emulate these traits - good taste, dedication and commitment, and to be the best we can be in the calling of our lives. For these three reasons I admire Darth Maul.
-Rob