Yeah I know it's a strange choice for favorite Python film, but it's just too irresistible to me; that many great sketches strung together with a movie budget makes for a damn-near perfect comedy. I could watch it all day. It beats sitting through the hours upon hours of Flying Circus for the really good stuff (that may be sacreligious, but I've seen that whole series and, like all sketch comedy, there's a lot of filler).
I appreciate the friend acceptance, good sir. I just bought my favorite Python film today: "And Now For Something Completely Different". I know it's not most people's favorite; in fact, I'd place both "Holy Grail" and "Life of Brian" (particularly) as better films, but I really really enjoy that one.