I liked it quite a bit, once I realized the film wasn't a comedy...or at least not the sort of comedy contemporary audiences recognize as such.
One interesting key for recognizing the film was more serious than its advertisements was seeing Hancock's reactions; this wasn't a comedian, this was a portrayal of a person on a slide downhill, who can't figure out how to get out of it, and is hopelessly angry at the reactions he's getting from people.
Granted, there were a lot of funny elements in the film, but they fit into the serious whole.