[ATDrake]

They'd be vastly more interesting if anyone ever bothered to expand them beyond the standard Zombies, Vampires, and Werewolves, oh my! horror movie clichés.

And maybe tried to mimic the style of the writing of the times a bit more instead of having these clunky modern-sounding substitutions into the original text. (I read PPZ, SSM, and PPZ: DotD from the library; 1st 2 were decent attempts at approximation, 3rd wasn't even trying and read like a cheap cash-in quickie.)

Some eldritch abominations wouldn't come amiss. In fact, there was a rather good Sherlock Holmes/Lovecraft anthology before all this, Shadows Over Baker Street, which spawned Neil Gaiman's excellent A Study in Emerald, available for free reading from his website. Admittedly PDF, but it mimics the look of a Victorian penny dreadful tabloid, complete with "period" ads.

That's what all these mash-up writers should aspire to.

Also, they should have more imaginativeness in the settings if they're just going to take mostly random popular elements and mix them up. Pride & Prejudice & Paranormal Investigations in the Wild Wild West, anyone? Or maybe Pride & Prejudice & Political Shenanigans in the Urban Courts of Faerie.

And finally, I can't believe no one's done a Northanger Abbey mash-up yet. You'd think that would be natural for it, what with the gothic horror mockery and all. Maybe they just can't find some properly alliterative item to "and" it with?