I think that Flann O'Brien deserves a mention. "The Third Policeman" is as everyday+surreal+funny+zen+insightful as Brautigan. I used to ask around a lot of second hand book shops for recommendations for somebody who likes Brautigan, and Flann is the closest I've come so far.
Mike Doughty of Soul Coughing released a book of poetry called Slanky. The music album Ruby Vroom (by Soul Coughing) is very unique and worth checking out.