HI!
I found this and thought you might be interested. Every year these guys do a mashup album called monster mashup. This year they have put out a one hour megamix and a few other mashed.
THe megamix is excellent! There are also links to some of the previous cd's!

The site is here:

halloweenhaunt.moonfruit.com

mashups on the site are:

Dance of the Demons - Remix of the theme to classic Argento/bava horror film 'Demons' with quotes from tony the pimp!
Missy Elliot vs MJ - 4 my zombie people
Busta Rhymes vs Ray Parker jr - bustaghosts
MJ vs Tag Team - Thriller Whoomp!
Does it offend you yeah vs Oingo Boingo - Doomed Man's Party
Does it offend you yeah vs ??? - Dawn of the Banshee
the haunted Mash-ion - rough demo from NOTLMM
gnarls barkley vs avalanches - crazy psychiatrist (in case you missed it!)
Its halloween! - Disneyworld Halloween song vs Insane clown posse
nightmare run - The Madness vs Gravediggaz
does it offend you yeah vs John Carpenter, Steve miller, vincent price - Halloween Royale with Cheese
Halloween with morrissey - From Son of Monster Mashup