One word to describe Eternal Darkness: masterful. It's one of the few games in recent memory that my desire to finish it increased as I played through it. And even once is not enough. I may take you up on that offer, Rick, and do a quick run-through tomorrow, just as I've played through Link to the Past countless times. And this game sticks with you...
I can still hear, in my mind, the half-whispered chanting of runes: Tier, Pargon, Antorbo, Cha'turgah, Xel'toth. Or the sound made while teleporting. Or any of a dozen voices saying "This... isn't... HAPPENING!" The feeling of dread walking through the mansion the first time. The satisfaction of watching the endings. And the insanity effects. Oh, God, the insanity effects. Not the blatant ones, mind you, but the more subtle insanity effects that make you afraid to get up from the couch at bedtime, that haunt your dreams, and make you see things out of the corner of your eye.