I was just about to post the Washington Post links. I felt very satisfied by the finale, but I still had a few things to mull over so I liked reading their analysis to get some new theories. That's one thing I loved about this show - it always made you think. There's far, far too much tv that just makes you switch off your brain and drool at the screen, and I loved that after every episode of Lost, I had things to think over and theorise for the next few days.
The finale wasn't perfect (hell, people would still be pissed off if it was just a 10 hour Q&A session with the creators!) but I do think it gave excellent closure to the major story arcs, and stuff like Juliet's "let's go grab a coffee" line tied very nicely back to earlier episodes.
(the terrible day-for-night rain machine filming was kinda distracting though. Shame they didn't have a bigger budget!)