Buffy was one of the greatest, and most undervalued, television shows of all time. It's been dismissed as camp by the Emmy people and by viewers who judge based on seeing one or two episodes - the problem being, that seeing one or two episodes can't show the show's true strengths - storytelling, character continuity, and plot continuity.
It's normal on TV shows to forget a character once they've left the show, to disregard a character's past on a regular basis, and to forget (or just ignore) what happened a year ago. And then, there's this show. On this show, there's a solid cast of 3-dimensional (but still consistent) characters, who actually possess *memories* of what happened before on the show! The show is full of instances where plots are foreshadowed, sometimes up to 2 years in advance, and there are references in Season 7 to characters that left in Season 3. It's so refreshing. Plus, the characters themselves are exceedingly well-developed. The dialogue is sharp, witty, and entertaining. The plots and direction are almost invariably flawless (and often inspired, especially during S4's Hush, S5's The Body, and S6's Once More With Feeling). The writing is perfect. Everything about this show is right, and it's such a shame that it never got the professional recognition it deserved.