15 of the best movie prequels ever

Indiana Jones and the Temple of Doom (1984)

Yes, the second Indy film is actually a prequel, taking place a year before the events of Raiders of the Lost Ark. Which makes the bit where Indy reprises the "shooting the swordsman" gag from Raiders a bit weird, but oh well.

Made while producer and director George Lucas and Steven Spielberg were both going through breakups, Temple is a somewhat darker effort than Raiders. The villains are a murderous cult engaged in child slavery and black magic, while there's an extended human sacrifice sequence that led to the creation of the PG-13 rating in America.