This is Spike's first episode ever on the show. Of course it's going to make the list. He was originally supposed to be a short-lived character, one of those vamps who shows up once or twice and then gets dusted fairly quickly. But Spike is nothing if not difficult to get rid of, and he charmed audiences so much that they sort of had to keep him around. School Hard is a fairly simple story about Buffy trying to balance her high school life and her slaying when a bunch of vampires crash her parent-teacher night. It's elevated by two main aspects of the story: everything that Spike does because he's awesome, and Joyce's greatest moment of the entire show when she confronts him in the hallway to protect her daughter. Molly Weasley, take note. Joyce did it first, and Joyce did it with an axe.