Frankenstein by EWB, of course
Witch Hunt by RUSH
What else?
Frank Zappa, Goblin Girl.
Bobby “Boris” Picket, Monster Mash.
Oingo Boingo - Dead Man’s Party
Rockapella, Zombie Jamboree
Toccata and Fugue in D minor, J.S. Bach (or maybe somebody else) - the stereotypical Halloween music.
I was going to add “Supernatural” by Ke$ha, but it won’t be released for two more months. 
Pet Sematary - The Ramones
The Killing Moon - Echo & the Bunnymen
Season of the Witch - Donovan
The theme from Suspiria - one of the creepiest film themes ever
Stuck in the Middle with You
Bad Moon Rising
Werewolves of London
It Came in The Night - A Raincoat
“Bela Lugosi’s Dead”, Bauhaus
Thriller
Time Warp
Not necessarily Halloween, but if you want creepy, D.O.A by Bloodrock.
Echo and the Bunnymen - People Are Strange (Or, if you prefer the Doors’ version go with that.)
Chiasm - Isolated (Maybe?)
Screamin’ Jay Hawkins - I Put A Spell On You
Rob Zombie - Living Dead Girl
If you want subtly spooky, then Peter Murphy - Cuts You Up would suit the purpose nicely.
The Cure - Lullaby (The single version ,not the remix.)
Since all the typical ‘halloween’ songs get old, my playlist is not traditional Halloween music but still spooky:
Flight of the Cosmic Hippo, Bela Fleck and the Flecktones. The greatest Halloween music ever written.
Kashmir, Led Zeppelin
Sweet Dreams, Eurthymics
In-a-Gadda-Da-Vida. (the full version, of course), Iron Butterfly
Lunatic Fringe, [I forget. The original one]
Day-O, the banana boat song. Harry Belafonte. Used in Beetlejuice, so it counts.
Teenage Frankenstein - Alice Cooper
Children Of The Damned - Iron Maiden
Raining Blood - Slayer
Halloween - Misfits
Halloween II - Samhain
Halloween - Helloween
The Theme to Halloween - John Carpenter
Mussorgsky’s Night on Bald Mountain.
Good one! 
Weird Al-Nature Trail To Hell
Forgot the Nekromantics Nice Day for a Resurection
Creature from the Black Lagoon – Dave Edmunds
Creepy Doll by Jonathan Coulton