The longest continuous campaign I’ve ever played would have to be the Star Trek campaign I started in 2000, after moving back to Albuquerque from Texas. I had intended it to be a mini-campaign, maybe a dozen nights of play, at most, and I was doing it mostly to get a few of our old gamers back into the fold. One of them was a huge Trekkie.
It lasted six years.
The game started with Last Unicorn’s rules, then migrated to Decipher’s in 2001 or 2002. We set the game post Dominion War, and I kept a lot of The Next Generation and Deep Space 9 “canon” for the game, but ignored all but the good parts of The Old Show and the movies. I ignored Voyager and Enterprise. The game centered on post-war politics and the rise of a machine race composed of von Neumann robots. We had a few rules — technology did what it was supposed to…no rewiring the deflector dish into a spiraling quantum whatsinator; the Federation and its culture was going to be explored…what was so great about it?; the tech that was discovered in the various shows and movies hadn’t disappeared…robots and sentient machines were just starting to show up and were based on the Ilya gynoid from Star Trek: The Motion Picture. Data was tech that had been largely unsuccessful.
We went through various ships and period from just post-Dominion War to about 100 years in the future, when the whole fleet was comprised of sentient starships, their crews who were as often as not cybernetically linked to the ship’s network. They busted the Borg by winning that enemy over with a better deal — the same fusion of tech and organics, but without the coercion…Federation crews either wanted to be wired, or served without the cybernetics. The cybernetics were not invasive, like the Borg’s. We did Borg better than they did.
Eventually, the issue was that the technology was so good, their understanding of the universe so complete that there was no real drama in the game… Game over.