Be sure to check out John Fante - The Bandini Quartet (or more specifically, Ask The Dust) if you enjoyed Bukowski. That guy is one of the most underrated authors of all time. It's probably the best stuff I've ever read, to be honest. Knut Hamsun is also a good one, if you can get a hold of his stuff that is (try Pan or Hunger).
But yeah, seriously, check out John Fante. I can't stress this enough. I'm grateful if I can get ANYONE to read his books.