Joss Whedon has a large Comic-Con presence. This year alone, the writer/director partied with fans, took part in a Firefly 10-year anniversary panel (arguably the convention’s hottest event), had another panel that was basically a one-man show, and in general took a great big victory lap for directing The Avengers, which one or two people saw.

But on Sunday, the Con’s final day, 2,500 people gathered in the confusingly named Ballroom 6BCDF to pay tribute to one of Whedon’s oldest and perhaps most-cherished works: Buffy the Vampire Slayer.

Though Whedon himself wasn’t present, the panel brought together people from each of Buffy’s incarnations: the not-so-good 1992 film that started it all, the beloved television show, and the hit post-show comic book. Original Buffy actress Kristy Swanson had been slated to appear, but couldn’t make it due to a “scheduling conflict.” Not that the crowd cared that much — even in a room of Buffy die-hards, the movie was barely a blip on the radar. Replacement panel guest Randall Batinkoff (who played Swanson’s boyfriend in the film) mostly sat there in confused silence while everyone focused on the TV show.

The crowd cared a lot more about two of the other guests: actors Nicholas Brendon (Xander Harris) and James Marsters (Spike). Brendon was a charming and funny presence, acting a lot like his on-screen alter ego (though far more potty-mouthed). Marsters was humble and gracious throughout, talking about his affection for the writers and how much the series continues to mean to him.

Other panel guests included Jane Espenson, who has written for both the show and the comic, and comic artist Georges Jeanty. The panel was moderated by series actor Clare Kramer, who played season-five baddie Glory. It must be said though: if anyone in attendance was actually a vampire, it was the fresh-faced Kramer, who hasn’t aged a day since Buffy.

Following the panel, Brendon returned to the stage to introduce “Once More, With Feeling,” the fan-favorite musical Buffy episode. The always-game Brendon even sang some of his more memorable lines from the episode, much to the crowd’s delight. Then, as the lights dimmed, the blissed-out crowd began to sing along to every Whedon-penned song. Now that’s something you can’t do with The Avengers.

Comic-Con 2012 Photo Round-Up: Buffy Turns 20