Another nation that could provide a rich variety of adventures.
Paris has cropped up a few times in my games as a highly recognisable location for tourist-y adventures, much like its role in many world-spanning movies. In this it’s a bit like London, but not as familiar to players based in Britain.
My first run of a straight spy game started in Paris, inspired by The Bourne Identity and featuring the subway and district divisions as well as more touristy backdrops. I also had a more cinematic spy game feature a car and boat chase along the east bank of the Seine, though I resisted the temptation to include the Eiffel Tower.
It’s also been a setting for adventures like a Doctor Who game fighting Nazis and dinosaurs in the early 1940s, Arthurian knights and Crusade-era vampires wandering all over western Europe, globetrotting adventurers and superheroes with a tendency to get into fights at or around famous landmarks, and Buffy being teleported away from Sunnydale by a monster trying to open the Hellmouth and having to get back without a passport.
I’ve never used it as a location for more than a single adventure or arc in any games, but I have considered it at times, like a supers or SF game mining Cool French Comics for characters and setups, or fantasy or horror cribbing from this thread about The Guide To Mysterious France.
I’ve also played the American translation of a French RPG, In Nomine. The adventure wasn’t set in France, however.
There are also supplements for France (or just Paris) for various real-world-based RPGs, and sections in Europe sourcebooks as well. I’ve seen Dreamhounds Of Paris for Trail of Cthulhu in action too. (Paris is a crater in Trinity. Sorry...)
Swashbuckling RPGs often feature Musketeers or analogues. The Revolution may or may not be an issue.
Likewise, Bretonnia in Warhammer started as just before the Revolution in WFRP 1 and then slid back to Arthurian High Middle Ages in the later wargame setting, while the Empire stayed early Renaissance throughout...