I thought I would give a quick mention to this site.
It's called the Horror Film Compendium. It's run by two very hardcore horror fans. Not only does this site feature reviews for hundreds of horror movies, but the site also lists the horror cliches the movies use.
This site is definitely worth a look, especially if you want to know what to watch on halloween.
http://www.xmission.com/~tyranist/horror/index.html