"Dagon" ...I'm not sure how easy it is to find, but it's a movie worth searching out. Fair warning... not for all tastes, and it may make you cringe at times.
It had really good effects, make-up, and a good twisted story. It doesn't star anyone I've ever heard of, but that sure didn't make a difference! I had strange dreams for about a week after watching this, and thought it was the scariest movie I've seen since "Alien".

It was directed by Stuart Gordon of "Re-Animator" fame, and the screenplay is by Dennis Paoli (think he worked for Full Moon Pictures).

...here's the blurb from the back of the VHS box... 'Based on a short story by HP Lovecraft, the undisputed master of macbre ...Paul and his girlfriend Barbara are celebrating the success of their new company on a yacht off the coast of Spain. When a sudden storm smashes their boat on a reef, Barbara and Paul swim to the nearest town for help. The decrepit fishing village of Imboca at first seems to be deserted, but unblinking eyes peer out from boarded-up houses. The strange inhabitants offer little help to the stranded couple. By nightfall, Barbara is missing and Paul finds himself pursued by the entire town...but a town of what?'
...if anyone else has seen "Dagon" I'd love to hear your opinion.
Back to original question:
What's the scariest movie you've watched that's been made since the year 2000?