I'm not much of a movie watcher so these are quite old.

Tim Burton's Corpse Bride - Animation/Comedy/Romance - Summary: Set in a 19th century European village. When a shy groom practices his wedding vows in the inadvertent presence of a deceased young woman, she rises from the grave assuming he has married her. The young man is whisked away to the underworld while his real bride, Victoria, waits bereft in the land of the living. Dark humor, hilarious.

A Beautiful Mind - Biography/Drama/Mystery - Summary: After a brilliant but asocial mathematician accepts secret work in cryptography, his life takes a turn to the nightmarish. A story about a mathematician suffering from schizophrenia. Great movie.

K-PAX - Drama/Sci-Fi - Summary: Prot is a patient at a mental hospital who claims to be from a far away planet. His psychiatrist tries to help him, only to begin to doubt his own explanations. It's based on a novel, one of my favorites.