One of my favorite quotes ever, from the episode "Help" in Season 7. The Scooby gang decides to do a Google search on Cassie, the Sunnydale high student who prophesies her own death. Xander finds some of Cassie's poetry, pointing to it as a sign of suicidal tendencies. Willow promptly rationalizes it by saying:
"I mean, a lot of teens post some pretty angsty poetry on the web. I even posted a melodramatic love poem or two back in the day...You join chat rooms, you write poetry, you post Doogie Howser fanfic. It's all normal, right? (Buffy gives her a look indicating that no, that's not so normal.)"
First of all, did Joss just HAPPEN to be looking through a magical crystal ball predicting his Internet future with Neil Patrick Harris? And second, the fact that this particular episode is based on the theme of prophecies adds a meta- aspect that is simply uncanny.