What should I GM for Halloween special rpg?

I am planning to run some fun one-shot for my girlfriend in Halloween. I want it to be fun, kind of old-schoolish horror, like those B-movies or some old scary story.

But I don't know what to run yet! Here are few options and ideas:

All Flesh Must Be Eaten could be one, but well, my girlfirend is not into zombies, so I quess it would be lame surprise for her. And let's face it, even though zombies are awesome it could be pretty lame. Come on. Zombies on halloween? As I might want to have some bloody zombie-action, that's not an option.

Call of Cthulhu. Well, this is real deal. Horror almost at its best. I was concidering 20's theme instead of modern age. There is something more sinister and spooky in 20's than today (today and tomorrow campaigns tend to be more equipment against monsters than "oh shi- I go NUTS over this tentacle 7-dimensional blob of eyes!!!!). So, 20's it would be. I was thinking, that I wouldn't run Mythos with great bad god and cultists (that is cool though), but something different. Here's the idea:
Fading away. So, at first main character sees people noone else sees. Later on, some people don't see the character anymore. So, for some reason (Cthulhu, it's in the title.... um no) main character is slowly slipping into the realms of the dead. Only problem is, is that a bit too slow paced, too moody, too tragic, too artsy?
Another idea is monster found in Yer Booke of Monstres (CoC sourcebook with Mythos monsters from various authors). Cannot remember the details, but there was this elder god (or something) what looks like a moon. So, character is amateur stargazer and finds this new planet/moon... what is (CTHULHU!!! Eh, no) some frikkin' huge monster! And when character finds it out, he goes nutz.

My Life With Master. Haven't played this yet, but it could be (tragic, dark and sinister) beer and pretzel (we don't have those in Finland I quess) game. It could be something in mood like Nightmare Before Christmas. Good quality is, that MLWM rules are quite easy to use. And the game supports 100% the campaign (well, you obey your master and then try to kill him!). That could be a go.

Kult. Well... no. I want to have fun in halloween. Kult has awesome setting, but it is a bit too violent, strange, sinister, dark, pervert, and so on for Halloween when you dress like witch or ghost and drink "blood" and eat "chopped fingers". So no.

CoC or My Life With Master. Which should it be.

If someone has really, really neat Halloween rpg adventure or something, shoot me with it! You can find my games I own here *klick*.