This is a fan video made by BadFred of youtube after being so excited by the Spike and Illyria pairing in Spike: After the Fall. It's set to Hysteria by Muse and uses clips from Buffy the Vampire Slayer and Angel as well as other shows.
This is an AU video set during Buffy the Vampire Slayer: Season 8 and Angel/Spike: After the Fall. Features Buffy, Angel, Spike, and it's set in Melaka Fray's future. I'll post the description in comments.