Trivia: While Joss Whedon considers the 1992 movie non-canon, two characters were carried over: Buffy herself (obviously), and her first Watcher, Merrick. Merrick only made one appearance on the show, through a flashback, and was played by Richard Riehle; in the film, he was played by Donald Sutherland.
Trivia: Season Two was the only Emmy winning season of the show's seven season run. Christoph Beck won for his score to the episode Becoming, Part 1 and the makeup team won for their work on the two parter Surprise / Innocence.
Trivia: Nathan Fillion auditioned for the role of Angel. Fillion later appeared as Caleb in the show's final season, and played Malcolm Reynolds on Joss Whedon's "Firefly."
Trivia: Except for Buffy, all of the First's incarnations at the end of the episode are the previous seasons' Big Bads, in reverse chronological order: Warren (season 6), Glory (season 5), Adam (season 4), Mayor Wilkins (season 3), Drusilla (season 2), and The Master (season 1).
Trivia: In the season 6 episode "Doublemeat Palace", Buffy has to get a job working at a local fast food joint. The writers went out of their way to make it seem like the most miserable, degrading job ever. After this episode aired, several fast food franchises in real life like Burger King pulled their ads from Buffy in protest.
Trivia: Principal Wood was given the gender-neutral name "Robin" because when the season began production, the producers were unsure about what gender the character would be. So they gave the character a name that could have applied to either a male or a female.
Once More, With Feeling - S6-E7
Trivia: Alyson Hannigan and Michelle Trachtenberg don't have many singing lines during the episode "Once More With Feeling". This is because Alyson threaten to come down with laryngitis should she get to many lines and Michelle actually did come down with it.
Trivia: In "Where The Wild Things Are," Willow mentions that she used to have a crush on Giles. This is evident in "I Robot, You Jane." When Buffy and Willow are talking at Willow's locker about Willow's new online romance, there is a picture of Giles and Willow in a magnetic frame on the inside of the locker door.
Seeing Red - S6-E19
Trivia: Many gay and lesbian rights groups were angered by the decision to kill Tara. Joss Whedon has argued that the decision was made not because Tara was gay, but because she was involved with Willow; had Willow remained with Oz, he would have been killed instead. Killing Tara was a way for the writers to advance Willow's storyline and transform her into Dark Willow for the season finale.
Chosen answer: Angel is saying that he is still jealous and Buffy recognizes that this is his way of saying he wishes that they could be together. That is why they both smile.