Here are a few I would love to see:
1. League of Extraordinary Gentlemen - Possible my favorite work by Alan Moore that isn't Watchmen. I don't think Hollywood actually read the graphic novels and based the movie on a brief summary.
2. Alien vs. Predator - This seemed impossible to screw up. You have two of the most gruesome and horrific aliens in cinematic history fighting each other and they decide to make it a PG-13 summer blockbuster directed by the guy who fucked up Resident Evil. It isn't rocket science, you have humans accidentally build a colony on a planet that is a Predator hunting ground for Xenomorphs. How do you fuck that up?
3. They Live - Don't get me wrong I love the original with Rowdy Roddy Piper, Keith David, and their epic alley fight scene over a pair of sunglasses. I just think a big budget remake would be fun. It was a really interesting story that I would love to see another director's take on.