These are only my top ten picks but the NES has plenty of other Halloween-themed titles. Here's a list of the rest that come to mind:

• Action 52 (for all the real sickos out there)
• Addams Family - Pugsley's Scavenger Hunt
• Adventures in the Magic Kingdom [The Haunted Mansion]
• A Nightmare on Elm Street
• Castlevania II
• Castlevania III
• Chiller
• Devil World (Famicom)
• Dr. Chaos
• Drac's Night Out (Proto)
• Dracula
• Fester's Quest
• Frankenstein
• Frankenstein: The Monster Returns
• Ghostbusters II
• Ghosts 'n Goblins
• Ghoul School
• Godzilla
• Godzilla 2: War of the Monsters
• Gremlins 2
• Kid Dracula (Famicom)
• Maniac Mansion
• New Ghostbusters II (PAL)
• Robodemons
• Simpsons: Bart Vs. the Space Mutants
• Swamp Thing
• Sweet Home (Famicom)
• Taboo: The Sixth Sense
• Werewolf
• Zombie Nation