"I Put A Spell On You Creedence Clearwater Revival"

VERY good song to do for sure...just make sure you don't use the creedence version as your foundation. A husband wife could pull this off great, just also make sure you have a SOLID bass tone backing you up ( even perhaps some reverb on the drumwork )...otherwise it can just fall apart.

Anyhow this is Halloween, so go nuts...perhaps do some stuff like the Hitchcock theme, or monsters theme, twilight zone, even Adams family. Even if you just use that stuff to trans between your main songs. Other then that check out some horror/sci-fi movie soundtracks, you don't have to scream a predictability insulting "monster mash" at someone to set a mood.

Past all that...just take whatever songs YOU enjoy doing already, and give them a darker tilt for the night. Way quicker to adjust something you know to fit in with a mood...then to learn a top twenty overplayed song list.