I need to know a good zombie video game!?

Okay, so I REALLY like zombie games and I want to get a really good one for the ps2. I would just ask the people in the store, but I'm like a peppy teen girl, so I don't want them to judge me or think I'm screwing around and give me a sucky one with like bad graphics and sucky blood. I want a really scary one, like one that'll make you **** your pants, you know?! Haha.