David Bowie on 'Extras' (2000)
Celebrity encounters were a staple of this short-lived Ricky Gervais series, with Kate Winslet and Patrick Stewart among the famous folks who played bizarro-world versions of themselves. Bowie's cameo was particularly brilliant: Gervais's character, Andy Millman, is depressed about selling out on a crappy sitcom, and unloads onto the legendary musician at a VIP club. The Thin White Duke uses that as an opportunity to improvise a song about Millman, getting the whole bar singing along with brutal lines like "pathetic little fat man" and "he's banal and facile, he's a fat waste of space." Ouch.