Flash Gordon is great, especially the Queen soundtrack... but what about "Flesh Gordon"?
If you haven't seen it, it's just like the original Flash Gordon, only with slightly naughty changes. For example, instead of Emperor Ming of Mongo, it's Emperor Wang of Porno. A funny thing about that one is that some of the SFX suck out loud, like a spaceship where you can see the string, and others are pretty good, like a stop-motion alien that goes on a rampage near the end of the movie.
Another favorite is Santa Claus Conquers the Martians- MSTers have probably seen it, but it's plenty odd enough on its own without the comments. I make a point of watching it at least once every Christmas.
