Over the years, there's a lot of movies I wanted to see made that never were. In horror, were:
Godzilla Vs Gamera -- when I was a kid I drew a comic for it. Gamera won.
Camps -- Always thought it would be cool if there were three camps, in a land of their own, gothic 1930 feel, one vampire, one werewolf, and one a small band of humans where Frankenstein continued to create an his frakenstein monsters. They would battle for survival and control.
I got my wish to see the prequel to The Thing 82 (disappointing), sequel(s) to Alien and Halloween.
Non-horror movies:
A New Trek -- Always wanted to see the Star Trek universe come in first contact with the Star Wars universe.
The Thrawn Trilogy -- love to see all three of Timothy Zahn's books made into movies. They take off right where Return of the Jedi leave off.
Ender's Game -- love to see this made into a movie. Great book. Oh, how about that. I see it's just been made into a movie to come out in Nov 2013. Cast really well:
Ender
Mazer Rackham: Ben Kingsley. Colonel Hyrum Graff: Harrison Ford.
Trailers: