This often overlooked 80s film's about a pair of sisters, (one the quintessential 'valley girl'),who find themselves - along with a few others - as the sole survivors after a comet's wiped out all terrestrial life. It's funny, clever, well written and acted.
Night of the Comet
A comet wipes out most of life on Earth, leaving two Valley Girls fighting against cannibal zombies and a sinister group of scientists.