The scariest part for me is when as Claire, you first discover Alexander locked away in that underground cell, and he lets out the SCARIEST moan I have ever heard. He sounds exactly like he has spent 15 years sitting there.
When Wesker, at the expense of good story telling, was brought back. I was horrified that the story would take a nose-dive and become a convoluted mess with ridiculous plot devices and shameless retcons. Good thing that didn't happen...
One of mine would be Alexander, but when he's loose: when Claire and Steve, thinking they're free, head for the ramp on the platform and Claire just pauses, seeing Nosferatu approaching. That music starts - just that thudding rhythm over and over - and it doesn't really matter that I've played it a dozen times and it's really quite easy. It's still terrifying.
Another part that scared the daylights out of me first time was entering the Ashford mansion and seeing those feet hanging in the foyer, and every time you climb the stairs you see a little more of the "corpse"... and it turns out to be a doll, albeit a very creepy one. Eerie.
Now cure me of my madness or I won't put my shoes on, ever.
Damn hunters allways make me friggin jump, but my scaries part would be the doctor in the prison. After the cutscene finished, i was expecting a few shots and he'd be dead but to my suprise, he just legged it towards me. I sh!t myself.