The very end of Braid, when it's revealed that the princess is actually running away from Tim. Mindfuck! What a brilliant game.

First time playing Portal.

First time seeing the sun set in Ocarina of Time.

Definitely my first encounter with a crimson head zombie in REmake. I was backtracking, walked past a zombie I'd killed earlier in the game without thinking anything of it, then all of a sudden it gets up, I'm thinking "WTF mate?! I killed you before!" so I kept walking thinking it would drag its heels as normal and the ****ing thing turns and RUNS for me!! I couldn't believe my eyes, yelled "HOLY SHIT!!" and managed to find a quick exit.....but yep, you guessed it, another one in the next room shot to its feet as soon as I entered.

Looking back at them they're really not frightening at all, it was just that as an RE player you're so conditioned to zombies being sluggish and easy to avoid. Genius from Capcom to throw them in.

My most recent holy shit moment would be this week, i upgraded to an HDTV and was trying my older games to see how great they looked. And to my surprise CoD4 and GTA4 Looked just about the same as before, i was not very happy.

either of three things:

1.) you didn't use a component cable or an hdmi cable. an hdtv won't help you if you don't have those.

2.) you need to get your eyes checked.

3.) the tv store cheated you and actually sold you a dud.

4.) you haven't set the new hd resolutions in your console.

i think it's 1. but in case you did everything properly, it's 2.

The crotch-grabbing in MGS3 (IIRC even on MGS2?)

The "Austin Powers" sequence in MGS2 when Raiden was naked.

Come on, I didn't cry there, but I was close to, that ending has to be one of the most moving scenes ever, you don't need to feel bad

On-topic, definitely that scene from MGS2 (and the crazy Colonel and naked Raiden part too) and the Psycho Mantis battle from MGS. And maybe some scenes from Silent Hill 2 and 3 (like when Pyramid Head is raping the mannequin in 2). Also, the first time you see a colossus in SotC

Gears 2 - playing the Reaver and Brumak-riding levels. And the first time I saw Gears 1 graphics.

BioShock - when you find out who you are.

Another one was when I realised the sun was rising when I started playing WoW the night before.

FFVXIII trailer makes it look like the biggest thing this gen.

I agree with Euphoria on the FF8 intro. After that, it didn't matter how horrible the draw system was, or how bad the graphics were.

Also, the nuke from WIC.... The opening of SuperMetroid, being recruited by special Ops at the end of Pilotwings SNES, Tekken 3 ending for Bryan and Hwoarang, Shadow of Colossus (the whole game), last level starfox GC, every metal gear solid. (I fell for that trap too, i don't know what I was thinking)

In the US we got screwed out of that moment because some dumb ass at SCEA decided to put the scene of Sephiroth running Aerith through in the commerical for the FFVII.

That has to be the all time EPIC FAIL ad. How can you put the games biggest spoiler in its ad?

Anway there quite a few. You guys have all listed good ones. Here are few off the topic of my head.

Grandia 2 - Finding out that the divine god was killed by the dark god and the church was just a ruse to empower the dark god. Oh and then finding the Gods weren't really Gods at all.

FFX - Finding out that the lead character was really just a figment of the imagination of the Fayts of Zanarkand.

Tekken - Kazuya coming back after being tossed into a volcano by Heihachi...I mean seriously WTF. Of course that was before Tekken went way weird with the whole Jinpachi thing...