I haven’t seen a lot of vampire movies, but Buffy was definitely the best TV series, for all the reasons @Tenpinmaster mentioned. I really liked Moonlight too, but it didn’t last very long. I just loved how they set up the rules of the vampire world and how it interacted with the human world – it’s one of the most plausible and realistic versions of a vampire story I’ve ever seen. Be forewarned, though, they stopped in the middle of a season and didn’t tie up any loose ends – if that’s going to drive you crazy, don’t watch!
I know you didn’t ask for books, but since you mention them in the details of your question, Sunshine by Robin McKinley is without a doubt the best vampire book I’ve ever read, followed closely by The Historian by Elizabeth Kostova. Two completely different styles of vampire stories, but both so good I couldn’t put them down for days.