Probably the best horror movie I've seen this year is Piranha. It was a good movie, don't get me wrong. Fun, gory, 3-D blood and boobs left and right. But just the fact that nothing is better than it pretty much sums up this year. A cheesy movie like that would normally not make the top 10 due to more serious fare, but there you go.
Still haven't seen Let Me In either, while I'm expecting it to be really good, the fact that it's another remake still shows there was a shortage of great new horror movies this year.