Night Of The Comet
This is that rare example of a dream inside a dream: she wakes up, but then it turns out she's still dreaming. Whoa.
Aliens
Another all-time classic, and a great fake-out.
Brazil
Just one of many amazing dreams in this breathtaking film.
An American Werewolf In London
Somebody please explain to me why "Nazi zombies" has become a genre, but "Nazi werewolves with Uzis" has remained so cruelly neglected.
Earth Girls Are Easy
She's just slept with the alien Jeff Goldblum, and she's having a bit of extraterrestrial sex panic. Perfectly normal.
Dune
More David Lynch insanity, this time with smoking face scrapes and cackling Sting.
Blade Runner
The famous "forest unicorn" dream, which had to be cut from the theatrical release.
ALF
Sorry about this one. The alien who lives among us is going through a Gilligan's Island phase, so he dreams that he actually lands up on the island and meets the Skipper. And Gilligan.
Dreamscape. Dennis Quaid walks into someone's dreams of walking in on his wife having sex. With everybody. (Clip may be slightly NSFW.)
The Fly
Geena Davis gives birth to a giant maggot, in a scene that manages to up this movie's already considerable WTF quotient.