james jean, who im pretty confident to say is leading the illustration game at the moment - started somewhere too, he's worked hard to get where he's at, and contrary to belief, him being asian has nothing to do with it (but it helps)!
i keep going back to his gesture sketches and arcylic/ink figure studies - theyre BANANAS!!
here's a few from http://www.jjeanius.net
like custode said, the way he captures 'movement' is practically impeccable!
and as custode said, the way he handles the arbitrary color is just so fresh looking to me!
check out more of his work at http://www.jamesjean.com and be sure to stop by his blog to see how he handles his illustrations!