Film Dope

The annual Halloween Special episode:
G-G-Ghost D-D-Dad
Homer has 24 hours to do a good deed before he can enter Heaven.
Scary Tales Can Come True
Bart and Lisa are tossed into the woods to fend for themselves when Homer cannot afford to keep them any longer, forcing the siblings to seek refuge in a dubious gingerbread house run by an ugly witch.
Night Of The Dolphin
Lisa sets free a dolphin, believing she is doing a good deed, but not realising the dolphin is bitter after being treated like a trained seal, and wants revenge.

The opening black & white sequence is a direct copy of the tv show The Munsters.

Homer (reading the newspaper): My horoscope - Taurus: Today you will die.
Lisa: It really says 'die'? That sounds unusually specific for a horoscope!

There are film references to Free Willy, and The Birds.

See here for details on The Simpsons Wiki.
See here for the script.