General sinema

Internet Movie Database: The most comprehensive database of movies on the net. A must for any serious movie-lover

Horror sinema

Arrow In The Head: Lots of very detailed reviews of modern horror movies and more..

Artsmagic: Cult movies distributor, specialized in asian releases.

Bloody Good Horror Films: A whole bunch of detailed reviews with very interesting bits of info (special info, deleted scenes, bloopers, etc..)

Carfax Abbey: Horror film database with hundreds of films, biographies of thousands of directors and actors and over 1000 gallery pictures along with video clips, horror wallpaper, horror convention announcements, etc.

The Diabolical Dominion: A great source of information for anything related to horror movies, among which biographies, cut scenes, interviews, a body count section and (of course) reviews. And the design is just superb.

E-Splatter: Great looking site, good ressource for modern horror movies, including reviews, news, previews and horror movie wallpapers.

The Flesh Farm: Detailed and interesting information for some popular horror movies, including a "did you know" section for each movie.

Guinea Pig: Features some of the most extreme (japanese) horror movies. This is gore galore!

Shade.ca: Great design, reviews complete with user ratings and more, all in French & English!

The cheezy, the bad & the sucky sinema

Bad Cinema Diary: Tons and tons of B-movies reviews. Did you say cheese??

Bad Movies.org: "A website to the detriment of good film"

The Bad Movie Report: "Face it -we love crap". Meticulously detailed reviews of movie (and highly enjoyable late-night read :), as well as other various ressources concerning the world of bad movies.

Horror Movies That Suck: Good movies and others not so good. Reviews done by several people so you can see more than one opinion for each movie.

Retailers

Unearthed Films: Help release extreme horror movies "for the good of humankind"