It's sort of embarrassing to admit, but my ipod has a Mega Halloween playlist with over a hundred songs (and if you think that's excessive, my Mega Christmas playlist will really scare you...)
When supercheap, programmable robotic-slave hands are invented, I'll be able to happily list all the songs for you (and will also never change the litter box again!) Most people are already aware of the classics (The Monster Mash, Purple People Eater, Thriller, Ghostbusters, etc.), and some of the wonderfully silly-cheesy stuff, too (like Sponge Bob Scaredy Pants, Werewolves of London, and so on), but if you're looking for a few quirkier-cool picks, these are 13 of my more unusual, less-mix-list-listed favorites.
A note for moms and dads: these particular songs are also pretty tame and kid-friendlyish (no bad words or scary-loud heavy metal), but, as always, each child's spook threshold is different (as are parental values regarding topics like death, witches and whatnot), so if you do have little ones, you'll want to use your own best judgement. Happy listening!