Vampire$ -> John Carpenter's Vampires
I hate to admit it but it's actually worse an adaptation than the Starship Troopers "adaptation." Although admittedly I do like the JCV movie. I used to like Starship Troopers until I found out the director made a mockery of Heinlein on purpose because Verhooven is a jackass. Did you even read the book?
Anyway.
As I understand it there actually is a reason for this. Basically, a studio ends up with the rights to an IP, and they sit on it because they suck at the one thing they're supposed to be good at. Then along comes somebody with a project idea, and the studio goes, oh that's similar to something we already have in the pipe. Then they steal that idea, tweak the script to include at least one or two elements from the IP, claimants an original work and they don't have to pay the original screenwriter, and churn out something that may or may not be any good, but is nothing like the IP, thus potentially making significant profits for the executives at the meager cost of pissing off the original IPs core fan base.