Quick Lost Review
(I haven't looked at other people's reactions, so apologies if I'm just saying what everyone else is.)
There were really two endings to Lost, and I had two very different reactions to them.
First, the notion that the sideways-world was some sort of pre-heaven. That was dumb, and rendered the sideways-world storyline even more pointless than it already was. It's clear that the writers wanted to give everyone a happy ending, realized that's kind of hard to do after killing off 3/4 of the cast, so they came up with a lame cheat. However this wasn't anywhere near as awful as the Battlestar Galactica ending. The BSG ending retroactively ruined the entire series. The Sideways-World ending to Lost only retroactively made pointless half of one season.
But I did like the main world ending. I think it gave a satisfying resolution to the characters. It didn't answer everything, but I didn't expect it to. I don't have any serious objections to it, and would give it a B+.
Those of you waiting for the end to see if the series was worth watching can go ahead and watch it. (Although feel free to skip all the sideways-world stuff in Season 6.)