I think that my appreciation of paintings is similar to that of music. I tend to enjoy novelty more than objective classics. In music this means I listen to a lot of Weird Al Yankovic, but also TMBG, Roy Zimmerman, and Jonathan Coulton. I do like classical music but the one I listen to most, Leoš Janáček's - Sinfonietta I like most for the eldritch, unusual theme.
In paintings, I do like van Gogh's work - Starry Night graces my Kindle case - but works that better demonstrate my character are novelty ones. Bosch's Garden of Earthly Delights is the best example.
Hokusai's paintings are among the best known in the world, and stand out as unconventional to western eyes. Here are some of my favorites:
A website devoted to him.
Wikipedia article on the man here.
BBC article here. Their podcast In Our Time devoted 40 minutes to him. I think their episodes are only available as MP3s for a few weeks but it appears you can stream from their site for an extended period.