I don't know about anyone else, but I don't tend to preorder games too often. I'm a bit of a scrooge in that regard - I'd rather wait until it goes down in price, or I'm able to trade in some existing titles to get it cheaper.
That being said, the last game I preordered was Guild Wars 2. Prior to that, it was The Elder Scrolls V: Skyrim. What about you guys?