If you're disincluding Silent Hills 4 onward, then I say do the same for RE.
RE is completely pathetic horror-wise (but certainly not fun-zombie-killing-wise), but rewind back to RE2 and you've got a slow-moving, hugely underprepared, under-equipped, clumsy-as-hell normal person barely surviving room to room while even the weakest zombies can kill you in a matter of seconds if you're unprepared. That s**t was SCARY, especially in the replay and RE3 when you have an immense, beefy, fast-moving and unkillable Tyrant following you personally everywhere you go. HOLY CRAP.
In the Silent Hill series, I'd say 3 was the scariest. Subtle psychological stuff is what Silent Hill is known for, but for SH3 they also sharpened the hellish noises, the totally f**ked up creatures, and the disturbing body horror to a keen edge. I thought I was immune to the Otherworld, but when the very walls start screaming and twisting in on themselves it's time to accept mental defeat and go off somewhere to cry.