The Abandoned (2007) was a pretty good ghost story. Ghost story/haunted house movies are a) few and far between & b) mainly crap. It just works out that way. The Abandoned wasn't particularly complicated or rife with twists but there was something satifying in it for me. I wouldn't say run out and throw down money for it in the theater but rent it when it comes out in time for Halloween.
Apologies but I am under the weather and can't summon the energy for a grand slam review. Here's a full review from http://www.twitchfilm.net/archives/007501.html.