Mirror Universe Star Trek. Still one of the coolest ideas in the Star Trek universe: the evil version of the Federation, whose logo is a knife going through the Earth and where you advance in rank by killing your superiors. And since Galaxy Quest is both a tribute to Trek and a relentless tweaker of the world of Trek, it hit me: evil Galaxy Quest would've been awesome. Heck, if there had been a Galaxy Quest 2, doing a Mirror Universe riff would've been one natural idea.
But instead of Van Dyke beards showing that people are evil, the characters would have genuine goatees. Only facial hair below the mouth, not sharply around it. Oh, and Sam Rockwell's character Guy Fleegman would be clean-shaven. (Is it wrong of me to want to see Alan Rickman as Alexander Dane as Dr. Lazarus with a mohawk?)
And they wouldn't call it "the Mirror Universe," because Galaxy Quest thoroughly renamed every bit of Trek lore for its not-subject-to-copyright purposes. What if the evil version was called "The Flipped Galaxy"? The "As you know, Bob..." explanatory scene would show that the Milky Way, instead of revolving the way it does in our universe, is revolving the other way. I can totally see a graphic of the Milky Way doing that.
And the Flipped, evil Thermians would always frown, and torture people using their tentacles (dangling! Oh noes!). The Protector would be named the Nebulizer (after the Galaxy Quest version of the phaser), or maybe the Death To Fatu-Krey. The ship's hull would have huge decorative knives. The digital conveyor (the Thermian version of a transporter) can be set not to teleport you, but to drown you. There's a torture chamber onboard staffed with those doll-sized, big-eyed, big-fanged aliens from that one rocky planet where Tim Allen as Jason Nesmith as Cmdr. Peter Quincy Taggart got shirtless. Dr. Lazarus's catch phrase will have changed to "By Grabthar's hammer, by the suns of Warvan, you shall swim through agony"; Alexander Dane will have to be forced by threat of being-crushed-by-a-Beryllium-Sphere to say it that way. The Fatu-Krey, the reptilian-insectoid creatures who provided the film's villain Gen. Roth'h'ar Sarris, will be food.
Let this be a film in my dreams. That's a safe way for me to think about evil.