Not necessarily a franchise, but an entire genre. I've grown tiresome of the FPS genre with only 2 or 3 shooters that I am remotely interested in given their appealing fun factor. Everything else feels boring, derivative, and just playing it too safe. Shooters just aren't fun anymore, they've just lost something that the shooters of old had.
Pokemon I lost interest after silver and gold and absolutely despise the franchise. They are so terribly samey and boring I hardly understand how people keep eating them up. Damn them and their good job at conditioning us from a young age.
Mario I don't care for much, I'll still play em but I'm not sitting on the edge of my seat for the next game.
I'm sure there are others but these seem to be the biggest culprits.
I'm more of a Fighter/RPG guy and they eat up a ton of my time. RPGs have to best value for my money given then length and possible re playability. And fighters are just pure competitive fun, far more so than shooters. The constant strive to become a better fighter, and the intense one on one nature of the game offers an experience like no other. Competitive multiplayer in its purest and best.