moodymuse19 has put together a list of Top 19 Moments in Supernatural. In some cases it's scenes, and in others whole episodes (because really, how do you pick just one from "In My Time of Dying"). It's a fun overview of the last 4 seasons.
Mo Ryan at the Watcher conducted a lengthy interview with Eric Kripke at Comic Con. You can read the full transcript here. Or, if you're a spoilerphobe like me, enjoy a despoilered version courtesy of the awesome missyjack.
From Mo's interview, here's what Kripke has to say about how the show has evolved since Season 1, and what we can expect in Season 5:
When we started out, we were going to make a horror movie every week. It was about the monsters, and it was about Hook Man and Bloody Mary and the urban legends and the boys honestly, in the beginning, Sam and Dean were an engine to get us in and out of different horror movies every week.That's what I'm talking about!
[Now] for me, the story is about, 'Can the strength of family overcome destiny and fate, and can family save the world?
If I had a worldview, and I don't know if I do, but if I did, it's one that's intensely humanistic. [That worldview] is that the only thing that matters is family and personal connection, and that's the only thing that gives life meaning. Religion and gods and beliefs -- for me, it all comes down to your brother. And your brother might be the brother in your family, or it might be the guy next to you in the foxhole -- it's about human connections.
What you'll find as the mythology of [Season 5] unveils, it's this massive, Byzantine mythology of angels and demons and what they want and their destinies for the world. But it's basically about two red-blooded, human brothers giving them all the middle finger and saying, basically, "Screw you; it's our planet. If you want to have a war, pick another one."