I bought Doom 3 on saturday on my 18th birthday, it's so amazing! I played it until sunup with headphones and the lights off and it freaked me out more than any film or game I've ever played before.
The only creepy part I had in what I've played of it was fighting the spiders (almost seems as shooter cliche eh?) But other then that none of it really seemed creepy. It felt like everytime you walked down any hallway it go dark and you heard the laughing, It did get kinda old after a bit.