I'm a huge fan of impressionism (Van Gogh, Monet), but that's like saying you like puppies.

A little more off the beaten path is Zdzislaw Beksinski: http://coilhouse.net/2007/12/the-beautiful-nightmares-of-zdz...

His artwork haunts me, even years after being exposed to it. The fact that he uses wood as a canvas makes it all the more fascinating.