Lol at the previous answer. NOTHING that Kirk has done has been more complex or advanced compared to Mustaine. Honestly, I feel that Hetfield is even a better guitarist than Hammett. Rhythmically and melodically speaking, Mustaine covers so much more ground than Hammett has. I like Metallica better, but Megadeth has had the better musicians for the most part.
@Combat Poopeater: I don't *think* I'm "clever and music-orientated (it's actually oriented, by the way; orientated is a false back-formation)." I am. I've been a musician for many years, and my studies tell me that your opinion is not the case, and I have the right to express my thoughts on your opinion as well as anything else I feel I should add. That absolutely doesn't mean I don't think you have a right to your own opinion (because you do), but if you really think that it's immature to disagree with someone and think differently, then you should keep those opinions to yourself until you grow a pair of balls and learn to spar. Telling me that I'm immature and that I can choke on my own ignorance will do nothing because those things are neither creative nor accurate.
Remember that the question asked about whom the better guitarist is. Knowing that preferences are inherently subjective, the only objective side of this is the level of technicality exhibited by both musicians, and I could show you many examples of Mustaine's playing that Hammett would not be capable of. It doesn't matter whether Hendrix taught Joe or Joe taught Jack or whatever. You don't have to prefer a guitar player because he's "better", because Lord knows that I could probably name 50 guitarists off the top of my head who are "better" than the ones we're talking about.