If you want to see a smart and truly scary thriller, go see Transsiberian immediately. In Salt Lake it's playing at the Broadway. We made a note to ourselves afterward: don't take the Transsiberian train from Beijing to Moscow. Just don't.
We made a similar rule after watching Funny Games: don't let anyone into the house especially if they want to borrow a couple of eggs. This remains the scariest movie I've ever seen.