When I need to jizz, I tend to look at amateur porn too. Never heard of Hclips, but I'll have to try it. I normally just go to HomeMoviesTube. There's decent amateur pics and sometimes short videos on Tumblr too of course.

I have indeed seen a few full-length porn spoofs of horror movies. My favorite of those is easily The Texas Dildo Masquerade. Ron Jeremy plays Franklin, wheelchair included, and the other characters are there too. From what I remember, it pretty much follows the same plot as The Texas Chain Saw Massacre, down to the opening graveyard shots, just with a lot of fucking. It's on Pornhub in full under the title Texas Chainsaw Massacre XXX Porn Parody.

My distant second favorite is probably The Addams Family XXX. Most of it takes place in their mansion and Fester orders a blow up sheep at one point. They even have their own version of the theme song, as heard in the trailer on YouTube.

I've seen a couple Halloween spoofs, but neither were anything special. Only thing I really remember is Laurie fucking Sheriff Brackett in one of them. Same with the Friday the 13th spoof. Jason doesn't fuck Pamela or anything like that though.

Two spoofs I've always wanted to see, but never have are Edward Penishands and Super Hornio Brothers. Both are from the early '90s and Ron Jeremy's in the latter as Squeegie Hornio. They seem worth checking out if you can find them. There was a Teenage Mutant Ninja Turtles spoof from a year or two ago as well that looked decent, but I've never seen it either.