Someone had to do it, I guess: the Parallel Universe Film Guide.
Browse here and what you’ll find are not imaginary movies — that is, movies that are referenced by other movies but don’t actually exist, like Mant! or Sand Pirates of the Sahara or Buckaroo Banzai Against the World Crime League — but entirely invented flicks that parody ones we know and love, or love to hate, or just hate. Like 2005’s Smells Like Indie Pretension, 1951’s Merry Murder Mishap, and the 1970s 747 series, 747 to Hell (1970), 747 to Hell in ’76 (1977), and 747 to Hell in The Bermuda Triangle (1979) (and not forgetting the 1980 parody, 747 to Hilarity).
The titles are funnier than the writeups, but still: the titles are pretty funny. Enjoy.