I remember that!

The part when Orochi drops the boulder on Nagi in Okami... and what happened next.

I'll think of more later.

MGS4 - Debriefing.
I was like, "Wait, wtf is going on here, is that B...!? HOLY FREAKIN' SHIT !

The scene instantly became my favourite MGS moment and one of the, if not "the" best moments in entertainment media for me.

Bioshock: Would you kindly...?

Seeing Donkey Kong Country for the first time at the E3. It was incredible and every gamer, watching it for the first time, mouth dropped in awe. The SNES was suppose to be dead and little life left in it and then DKC comes on the screen and blew everyone away.

No contest.

Also, "We don't go to Ravenholm"... Damn it...

FFX - Finding out that Auron was dead all along,,,, and Tidus was a dream, WTF (the coolest character and the main character are not even alive)

FF VIII - The intro was a WTF moment in its entirety,,, plus when seifer destroys odin, i mean holy WTF

FF VI - When Kefka destroys the world,,, i mean this is the first time that an evil characters actually wins

Silent hill 2 - PYRAMID HEAD, seeing him passing next to you is a WTF moment

Resident Evil 2 - Discovering that when you finish the game with a character and then continuing with another the game for that other is entirely different

Resident evil 1 - The dog the jumps through the window of course

Uncharted - Seeing it for the first time ever on my new HDTV

Oblivion - The first time you exit the prison into the world map,,, and you discover how huge the game is

Shadow of the collossus - Seeing a collossus for the first time ever

Castlevania Symphony of the night - The game starts with a "Final stage bloodlines",, i though at the moment that my copy was at fault,

Totally this, I remember Yuna started doing the dance thing, and pyreflies start coming out of Auron, I'm like WTF NOOOOOOOO!!

Other than that, MGS2 freaked the shit out of me when it started going all crazy. Mostly because my place had just been broken into, but I got home before they made off with much. The next day i cleaned up and started up MGS2 and all the weird shit started happening, I was sure the guys had stolen my game, and replaced it with some pirated messsed up copy.

My two most recent ones that I can think of:

Would you kindly....? froom BioShock

Ending of HL2: Ep2. It came out of the fucking blue, literally. After my greatest feat of strength and BAM! GG. G F*cking G!