I’ve got to disagree with you, on the other hand, regarding LOST’s shift after season 3. We’ve certainly had great episodes: The first eight or so episodes of season 4 together (up until Rousseau’s death) reached the show’s quality and artistic peak to date, and season 5’s finale was the best of any season ender, IMHO. But many other episodes found the show focusing on plot, mysteries, and action at the expense of character, and the show often lost what either Carlton or Damon once called LOST’s genius — that it’s as much about characterization as it is about plot or mysteries. And it’s primarily in the characterizations where we end up focusing on the show’s primary themes: redemption, fate vs. free will, religion vs. science, etc.

I’d even argue that many of the mysteries have already been explained satisfactorily. For just one example, the central role of Smokey with respect to the show’s primary theme of redemption has already been made clear, I think: to cause people to evaluate their lives and in some way be judged. Everything else except for who has controlled Smokey (for the record, I’m betting it is a neutral Cyberus-like watchdog/Island security system that has been employed to both good and evil ends over the course of the show) is mildly interesting but ultimately superfluous to me—Smokey’s origins can stay a mystery, as far as I’m concerned. I’m ultimately satisfied with a mystery’s status if its role in relation to the show’s central themes — and particularly that of redemption — has been explained sufficiently.