I think the style on the left looks best. It looks more professional and '2015' if you ask me. Pixel art is also great, but I feel that the smooth style is more lineair with modern games, so I think you would attract a much broader audience indeed. Pixel art seems to be more reserved for the pixel art fans.
I really do like the smooth style character, I think you did an excellent job there, it looks magnificent. This is going to be a ninja-type of platformer? If you could get the environment and other characters to look just as great, I think you've got a great start for a game!