I did stop watching Lost a while back, but I'm not gonna brag about it. I'm actually kind of disappointed. My best friend was a faithful Lost viewer, and I always felt like he was in on something that I was missing out on.
Anyway, no, I'm not here to tell you what I thought of the finale. Instead, lemme just say this:
In my mind, there are three kinds of serial entertainments — and this goes for books, movies, TV shows, any medium where a serialized story is being told. There are the stories where you keep watching/reading/whatever because you have to find out what's going to happen next, or how it all ends. Think the old Republic cliffhanger serials. Then there are the stories where you don't really care that much what events occur in the plot; you're just hooked on the characters or the setting or the writing or whatever. Finally, there are the stories where an ambiguity has been set up and you're just dying to know what it means.
In my experience, types one and three — the plot-driven and the mystery-driven serials — are always a let-down on some level or another when they finally end.
I'll give you a for-instance. I got out of the habit of watching "The West Wing" after the start of the fifth season. Sorkin left, they radically changed styles, and I just wasn't enjoying it any more. So I turned it off and didn't go back.
That meant that, effectively, "The West Wing" ended for me with Zoe's kidnapping and Bartlet's middle-of-the-night resignation. (Er. Spoiler alert for a seven-year-old story.)
If I'd been watching 'cause I wanted to see how it all played out, or 'cause there was some mystery that wanted solving, that would have been the least satisfying finale ever. But as it is, I actually kind of enjoy stopping there. Because it's organic, to borrow a grotesquely overused phrase. What happens in that storyline makes perfect sense, and how it ends is inevitable in light of how it began. So I can pop in the DVDs, watch right up through that episode, turn them off and go on about my life secure in the opinion that it was pretty much the best TV series ever.
I think whether you enjoyed the Lost finale probably depends on whether you were watching for the plot, or for the mystery, or for something else. If you were in it for the plot — as I was, back when I watched the first season-and-a-bit — then I really don't think any ending could have felt truly satisfying.