Here are some of those ideas that deserve to make a comeback, especially now that we're either running low on concept or are doing a lot of "re-imaginings".
We have Sweeney Todd: The Demon Barber of Fleet Street as a slasher-serial killer-musical, as well as a slasher-fied Phantom of the Opera (1989) (starring Robert Englund as our skin-wearin Phantom!) and the Johnny Depp starring From Hell, but other than those titles, we never get to see any slasher movies set in the simpler and more unhygienic times. Wouldn't be great if we had a band of cowboys being stalked to death by masked loon? I'll pay to see that!
Let's face it, Cartoon violence might be funny, but if you put it in a real world context, it can kill. And they'll be pretty good kills, I assure it! So far, the only titles to do this would be the two Terror Toon movies, and one of them ain't even good!
And these are some of my dream set of slashers. Yes, I do know there's plenty more titles out there waiting to be uncovered, but I'm sure half of them, or at least a fourth, will be another Friday the 13th, Halloween or A Nightmare on Elm Street clone. It's rehashing like that which ends up this sub-genre to be nothing but cliched, but the years are young and people will learn, and so do these titles!