Re: Crossovers that never happened but you wish would
The season opener of Fringe had X-files showing on a TV in the beginning and later the "X" department was mentioned in the congressional hearing. So, fiction and fact in the same show?
Take a page from Stargate SG-1. When the series in the series Wormhole X-treme was being made, the Air Force let it.. plausable deniability. In a reality where the X division exists, letting a series be made about it is the perfect cover for it's operations.
"They have to help the viewers let go. Firefly did a movie to wrap things up. Buffy the Vampire Slayer continued on as a comic book. Heroes gradually lowered the quality season by season until we were grateful it ended.” - Sheldon Cooper