I'm going mildly spoil the movie Drag Me To Hell, but I'm not going to give away anything major.
The only likable character is the "Hi, I'm a Mac" guy. He's actually a decent actor (though it'd be nice to see what kind of range he has), and his character was pretty sympathetic.
The main character is just stupid. And selfish. But mainly stupid.
The psychic guy would have been likable, except he was an extortionist. "Oh, you're going to get dragged to hell by a demon tomorrow? Gimme ten grand and I'll maybe give you a solution."
Everyone else was just a cookie cutter character or an asshole.
And Baba Yaga was a disgusting bitch.
The movie had a number of moments that were simply absurd. Like the "I conveniently have an ANVIL hanging from the ceiling of my shed" scene. Congratulations, evil gypsy spirits can be temporarily defeated by the same tactics you use against Wile E. Coyote! It was also predictable to the very end.
This actually could have been a seriously creepy, disturbing film, but it was just painful to watch. It's definite MST3K fodder. The ending of the film, which I won't spoil, wasn't dramatic like it was intended to be; instead, it had the entire audience laughing at the film. That's generally not the reaction a horror movie wants.
In summar: It sucked, but it had the potential not to.