I almost went with Paranoia as my game of choice. Back in the 1980s, I was frequently the GM for those games, and apparently I was really good at being "The Computer." So good, in fact, that most characters (and their clones) didn't make it back from most missions. It's definitely a weird game, but a whole lot of fun with the right people.
Another strange one I once owned was called Dream Park. A lot of what I remember may not be accurate, but I'll try to get it right. The idea behind the game was that the game took place in some kind of futuristic game park where there were (for lack of better description) holo-decks, like the ones we saw in Star Trek. The characters could die during their adventures, but weren't dead in real life, so they'd be back during future adventures. Each time you played, it could be something different...a pirate adventure, a medieval adventure, science fiction or even a Victorian-era murder mystery. There were even suggestions to combine genres for something really different...like a medieval adventure where the players are aliens from another planet.
Where it had issues was that players had a hard time getting invested in the game. Knowing it wasn't really "real," kind of took the fun out of it. I don't think they really gave a good reason why players would care about adventuring in a fake futuristic holo-deck. At least, that's how the players I played with felt about it at the time.
(If someone has better knowledge of the game than I've provided, feel free to correct me. It's been 20 years since I've even seen the book).