This post has details about the movie, so if you don't want any of the scenes spoiled for you, quit reading
That said, I saw the Hills Have Eyes maybe a week or two ago. I thought that, much like Wes Craven's other work, it was a very mediocre plot, but the acting was good enough to make it at least an enjoyable view. Some of the scenes struck me as highly unrealistic, and the movie itself was pretty predictable, but I don't feel cheated out of my free movie pass and time, so it must have been pretty good.
Because of the acting, I felt the psychological horror of some of the movie was extremely effective. For example, in what in my opinion is one of the more disturbing parts of the movie - the rape scene - I think that the girl playing the victim was fantastic. She was very convincing during the rape itself, almost uncomfortably so, and she maintained a real feel of shock, terror, and paranoia following it and throughout the rest of the movie. In fact, I think everyone did pretty brilliantly acting except for the man who played the husband/father (the young one that was sortof a hippie liberal?). He didn't seem to consistently show enough emotion and was almost unrealistically collected.
I must say, The Hills Have Eyes was one of the first movies I've seen in a while that had a scene that really bothered me and gave me that "skin crawling" kind of feeling (and considering I've recently seen The Audition, Battle Royale, Saw II, and Hostel, that says somehting). It wasn't because it was gory, it was the sheer wrongness of it. I am of course referring to the scene where the mother is being sexually molested by the "leader" of the deformed folk while her baby is being kept at gun point and her daughter has just been raped nearby. Something about that was outright sickening to me.
Anyways, I'd say it is probably worth seeing on video, but most people shouldn't waste the $8.50 if they're into a movie with a good plot line. It just wasn't consistently realistic (for example, how the heck did he get his dog back in the end when he left it back in the town...?), which can sometimes be worse than a movie being consistently unrealistic. It is definately entertaining though, and if you like the genre, it is definately a must see.