Over in LiveJournal land, there's this "meme" going around about describing fandoms as relationships. It's not really my sort of thing, but it did lead Rachel Manija Brown to ask why so many people are so mad at The X-Files:
I had a different experience: I drifted away slowly, I think during the sixth season (around "Post-Modern Prometheus," the episode where Mulder repeats a bank robbery day, the baseball alien episode, etc.) The show and I just seemed to be going out of sync with what had made me love it in the first place. So I had stopped watching long before whatever led to everyone else's terrible break-up.
So: what the heck happened? Why are you all so mad?
People explain it to her in the comments. At great length. And it's pretty amusing.
(I had also stopped watching well before the show went totally off the rails. I was never all that into the "serious" episodes, either-- my favorites were always the ones where they mocked themselves-- so I didn't feel betrayed when those started to go all goofy, but it's amusing to read what more serious fans thought of the show's final seasons...)
I drifted away at the end of the fourth season and beginning of the fifth season. The quality of the bottle episodes had gone down sharply, and the conspiracy episodes were a prelude to the sort of thing that's apparently killing Lost - you could tell the writers had absolutely nothing in mind as the ultimate "truth".