Did you know that Marc Jacobs is the head designer for Louis Vuitton? You're implying that Louis Vuitton and Marc Jacobs' diffusion line, Marc by Marc, are two completely different things, when in reality, they are not. However, even though Marc creates works of art--rather masterpieces--at each line he designs for, I would have to choose Marc by Marc over Louis Vuitton. Marc by Marc is younger, fresher, and simply wearable, whereas Louis Vuitton tends to be a little bit more high fashion and more the grown woman. But don't get me wrong, both lines are amazing and I worship them, but Marc by Marc wins in this case.