This 1982 'Slasher' film is right on the money. It has all the ridiculous you could want...and teen girls in nightgowns, bouncing around.
Plot: Crazed bloke escapes from prison and kills teenagers with a power drill. Lucky for him, there's an abundance of victims at a slumber party.
Watch out for the stand alone best scene, pizza anyone?
Budget: $250,000
Good line for the series, the drills get bigger and the chicks get hotter.
Fun Fact: Written by feminist Rita Mae Brown and directed by Amy Holden Jones, a complete contrast to the male driven genre and a great tribute too. Three sequels followed; Slumber Party Massacre II (again, female directed-Deborah Brock and produced by Roger Corman), Slumber Party Massacre III and Cheerleader Massacre.