You've got some good ones! The movies where Arnold tries to pass as an everday man is funny in itself but Phil Hartman was brilliant in Jingle All the Way. My favorite Christmas movie is Santa Claus Conquers the Martians. I had heard all the negative reviews and jokes about it before watching but I liked the concept and the Santa was perfect.
I’ve only seen some of the MST3k take on Santa Clause Conquers the Martians but it definitely seems like a true piece of art.