For me, it would have be tie between Amnesia: The Dark Descent and Resident Evil(Only played the Gamecube version.).
Both have incredible atmospheres and soundtracks to further the dread.
While you do have guns in RE, ammunition isn't exactly abundant(At least, in the early to mid game.). Also, the Gamecube version had a feature where if you don't land a decapitating headshot on the zombie or burn it's body when it "dies", it will reanimate as a Crimson Head. Crimson heads are A LOT faster than regular zombies and do even more damage. By the way, the fuel is also limited, and there are more zombies than there is fuel to burn, so you'll more than likely have to leave a few alive or try to kill them in a pile and light the pile up. Or go for a headshot, which is honestly easier said then done, due to the lack of precise aiming.
And let's not forget the other abominations!: Such as zombie dogs, lizard men, hornets that swarm at you, giant sharks! And the traps that could kill you in gruesome ways if you're not fast enough to react!
Definitely a worthwhile consideration, especially since there's remake of the REmake(Gamecube version) coming soon to PC and other gaming consoles!