The mythology of lost might be based on Sci-fi, but there isn't much Scifi currently in the series, other then the alternate reality story. I mean, in the last two seasons we had the time travelling (Desmond's and the rest of the islanders), moving the entire Island, the time continuty differences between the Island and the rest of the world, explanations for it, info about how to get off the Island and why its so hard to find it, etc.
Anyway, the characters, most of my favourite 4 are gone. Faraday (as he provided more answers to questions than anyone else, and he was just a cool Scientist), Charlie (who didn't like him), Desmond (maybe becuase he's British, and was an underdog in trying to win the respect of Mr Widmore - who doesn't like rooting for the underdog) and Sayid (luckily still around). Sawyers good for laughs, but can quickly get tiring (imagine an entire episode of Sawyer 1 liners) and Jack, I respect but is too stuborn for his own good. Kate, doesn't know what she wants. Hurley, Miles, Jin, Sun, all good secondary characters, but you couln't market Lost soley on these characters.
I know it sounds like I only have complaints about Lost, I enjoy it, but its not as fun as it used to be. Gone down from 'must see' to 'will see' (heck I've even waited a few days and watched some of the eps on Sky 1).
I'm not particularly concerned about the Island (mostly got that figured out), but hope to find a justified answer as to who exactlky smokey and Jacob are.
FlashForward is scifi entirely becuase of the premise, but not too much else, I know. Humand Target, I know its based on a comic book and not much else. V has aliens (pretty aliens as well with the 'companion' from FireFly in it). Fringe, even standalone eps I look forward to, becuase of the crazy 'fringe' science aspect of it, even with the 'monster of the week' format (I usually hate those types of shows, prefer something much more serial).