I just remembered one.
Some WW2 game on the Gamecube, I forget if it was a CoD or MoH game, or something else (been years since I played it). Leaning towards MoH.
Anyway, in one mission you are in the back of a truck, disguised as a German soldier, being driven through an occupied town to a tavern where a contact is waiting. The truck is driven by a resistance member who you've been working with for a while up to that point. It gets blown up by a bomb, killing the driver. I felt like shit after that.
Shortly you arrive at the tavern, which is packed with soldiers. The contact is waiting out back, but the way back is blocked. You have to make a distraction by getting the soldier at the piano to play a song. Soon, everyone around is joining in on the singing, giving you the chance to get out back. The joyous atmosphere really lifted my mood, even if they were the "bad guys".
Then once you get out back, you have to make another distraction by knocking over a beer bottle, which gets a couple soldiers into a fight. That was funny.
Oh yes, how could I have forgotten? Never before have I had so much hatred and respect for a character!

Zelda: Ocarina of Time - I was amazed with the 3d graphics, great use of sound effects (hitting your sword upon wood or metal or where you were walking gave different sounds), daytime and nighttime world differences.
Silent Hill - This is where I found my calling. I liked Resident Evil, but this was just so much more to me. Shame I refuse to buy a 360 or PS3 at the moment so I could play those ones as well.
Final Fantasy III (snes) - To this day still my favorite in the series, besides the first one. VII is great too, but I still like 3 better. The huge roster of characters and storyline, there is just so much content packed into that little cart.
Diablo - Wow, I never realized how many people were such liars and cheaters playing video games. It literally made me hate cheat systems. But the game was amazing if you had a group of people playing together the way it was meant to be played. PVP was useless unless you just wanted to see who had better cheats.
Mario Kart 64 - 2 players was awesome on the snes, now you mean I can have 4 players? The only thing this game was missing was a track editor or at least the ability to creat your own battle courses.
The Sims - I never really caught onto this game. a g/f at one time really loved this and demanded I played it with her. What a waste. Wow, just wow. You mean even though my guy works in the military I can't brutally pummel anyone for leaving garbage laying around my house? If you want a sim where you have to work, play Harvest Moon, way better.
Last but not least
Gran Turismo - Not really a whole lot of in depth play other than racing for money, tuning up your car to make it go faster, and race some more. But I think the thing that surprised me most on this was the fact you have to pass a driving test to get your licenses before you can even race. Geesh I used up so many memory cards with this game saving replays. The best part was being able to go head to head against your friends to see whos car was faster.

Ditto on Zelda. Although mine was more of the final battle and escaping the tower like castle.
Lufia Series: This is what lured me into the RPG genre when I was 5...Ah, the good ole days. Now that I recall this, I still have my SNES and the second Lufia game....
Half-Life 2: Using my Gravity Gun to fling shards of glass into my enemy's skull.
Halo: Just got the installer from a friend via Xfire. God this game bought back a lot of memories. My first spilling of Covenant blood, the pistol before it was fucked in Halo 2 and 3, and using a needler to blow up my enemies. Oh, and online. Tons of fun still....
GTA San Andreas: Mowing down pedestrians in my Cadillac blasting Depeche Mode.
That's about it now..

I've had many over the years, but perhaps the ones that stand out the most pronounced are these:
-- Battlefield 2: Discovering 4 members of an enemy clan hiding in the hotel pool on the Oman map and knifing all of them in about 4 seconds. One of my teammates witnessed it and I was a celebrity in Teamspeak for the rest of the night.
-- The tornado in No One Lives Forever 2.
-- The endings to Bioshock and The Witcher. (I could see The Witcher being made into a Hollywood feature with that ending.)
-- Okay, this one is almost a cliche now, but the first glimpse out of the cave into the scenic vista in the original Far Cry.
-- Parachuting into Mexico City in the intro of Ghost Recon: Advanced Warfighter. I always knew Mexico City was big, but the grand scope of it from that viewpoint made my mouth drop open.
-- So many moments in Operation Flashpoint that make this one of my all time favorite games despite its bugs and glitches.

My moments:
- Far Cry 1 --> leaving the cave for the first time.
- Medal of Honor 1 --> storming the beach
- Half Life 1 --> the intro (trainride)
- GTA 3 --> first mission at the beginning, when you hear that sweet song on the radio
- Wolfenstein 3D --> discovering a secret room for the first time

Almost forgot about a big one ...
Noctis
When the realization kicked in that no matter what I do, I will never be able to see everything the game has to offer. Or to quote gamerswithjobs:
The purpose of the game is to explore and document a galaxy of nearly eighty billion stars.
The sheer scope of this game is just beyond mindblowing.

Half-Life 1 - Tram, as stated above
Half-Life 2 - "We don't go to Ravenholm" zomgwtfamazing
Half-Life 2 Episode 2 - The beginning sequence with Alyx and the very end of the game
Suffice to say, I love the Half-Life series
Metal Gear Solid - Monologue after you fight sniper wolf
Devil May Cry - classic move, you fling up a puppet with your sword and shoot him in the air until he blows up. raw
Fallout 3 - the intro, you instantly care about the world
All I can think of now ...

So do I...=)

Elite, docking to receive 'INCOMING MESSAGE' rather then the usual trade screen.

Oh lord ... I have the old platinum edition, half-life 2: goty, orange box and l4d. I think I have every valve shooter now, and I beat most of them (still not opposing force and blue shift). Here's my screenshot, I couldn't fit all my games in one screen.
I'm White_Hamster on Steam, if anybody wants to add me.

Jesus! Well, I can not get Age of Chivalry to run (Always crashes after it loads.) so I am gonna try out riot act. any other good mods?

I played the hell out of some Sourceforts. It's a base building game meets CTF. There's a build round where you get the gravity gun and build a wall and flag fortress, then you have to steal the other team's flag and get it to your flag. It's really fun, not sure how healthy it is nowadays. That's the main one I played, I liked how Zombie Panic: Source was going, then I got L4D

The ending of Tales of Monkey Island Episode 2: The Siege of Spinner Cay

Are we talking about FF3 or FF6? Because FF3 didn't impress me that much, but 6 is the best title in the series IMO. I'm just asking, because you crazy Americans keep calling the sixth part number 3.....

The Revelation in kotor was awesome.