With this site so rife with nostalgia there is no way that the memories have not washed over many of us.
So, have you run across a game here on GOG that brings back vivid memories of the time you played it?
My first time playing Die By The Sword is pretty vivid I played it for the first time at a lan party surrounded by Dr. Pepper cans and a guy that smelled like taco meat.
we spent the entire night hacking each other to pieces and then followed it up with some GTA jesus bus carnage.

Oh, die by the sword... That weird game I borrowed from my friend and he never got it back... Yeah... Beautiful memories...
Ooo, and because Die by the sword I remembered Fragile allegiance! (it has to be connected. Somehow. Oh, I know... I still have friend's CD with FA! We moved to another city and everything I had, even borrowed, moved with me :D He never wanted it back :D)
Oh, and Fallout. Of course. Hours and hours and hours of fun on my old PC...

I'd say both Fallouts, particularly fallout 1. I saw it first at a friends house and it was just so interesting I could sit next to him as he played and watch and still enjoy the quirky humor and story. I manged to get a hold of ti myself and gleefully jumped in began my adventures.
The coolest thing that comes to mind is watching Dogmeat solo a deathclaw. So badass... I wish I could find the cafe of broken dreams in Fallout 2...

fallout 1 always brings back memories when i tried the demo for first time and i was shocked, that must be one of the demos that i played so many times xD

I was in my local Electronics Boutique in the late 80's. I saw a flat black box on the shelf...
Wasteland. I stared at the front (an overhead shot of the long shadows of a party of people standing in a ruined street) for minutes. I read the back. I hyperventilated. I cried. I was nine.
I spent all of my birthday money on it, then spent two weeks trying to figure out how to play it (I needed spare 5.25" disks AND changes in my Apple's boot configuration).
I finally managed to load it up and make backups. Then I built a party of Rangers that had real guns (!) and walked off into the desert, and promptly died in Highpool. Heaven.

Time Commando (not on GoG yet, but i hope so) :) at my uncle's house, computer with Windows 3.11 heh I was there for maybe five days -> five days of playing and i only got to WWI :P and Duke! damn.. so many memories :D

Yeah memories I have. They stickied have.
Some moments from x-com apocalypse. My big brother was playing it in a very dark room and I watched it. The music was scary. Brother was exploring the tactical map and all the aliens were still in hiding. Then he came to a door. He ordered one of the soldiers near it. It ope**SKRIIIIK**.... a brainsucker came from the other room and jumped onto the guy and sucked him. Then the guy started to shoot his friends. I loved the game after that. I was something like eleven and that moment was sooooo scary.

M.A.X.
i totally remember our real-life espionage experience while playing hot-seat multiplayer with my friends. there was one rule - all other people leave the room while one person makes his turn in game. besides that - there were no rules, we used sthetoscopes to listen to what's going on behind the door, special mirrors set up to see the movements, cassette decks with record buttons left in "on" positions, all kinds of stuff. once i even managed to unmount one of the wall outlets to peek through the hole). in other words, we made this great game even greater with real-life experience)
p.s. a person whose intelligence service was better usually won the game)

No, I am a loser, this is my first time playing any of these games, but hey at least I have the chance now, am i rite?

When I was younger my mom had a subscription to PC gamer (one who got me into PC gaming) and I got a disc full of full games with it, one of those games being Descent. I put that game in and it held my attention more than Doom II for a while (Doom II I still play everyday to this day). When I saw that Descent was on the list of games I had to sign up for this beta. When I got my copy of Descent and Descent 2 it was like reliving my childhood which is great.

The first games I played was Red Alert (not here thou, but can dl for free) and KMD! I dunno, i was about... 8(?) when I first played it. Awesome to just jump around and shoot everything up =D Not gonna buy it from gog... I have experienced many games I thought kewl when kid and played em' few yers later only to notice they are not quite so good as I remembered. Of course, some games you can still play for hours and hours (fallout 2, first time playing it actually and Freespace 2, etc. etc).

I can't say either of the Fallouts since I've kept playing them on and off, Giants: Citizen Kabuto though, that brings back memories. :)
I got it bundled with some card (don't remember if it was sound or graphics) and tried it, not really my type of game but I wanted to see why it was written up as underrated in some review I read.
When I reached my first in-game movie and laughed I just knew I had to play it, I never did enjoy the game itself that much, it was ok, not more, but the outrageously silly movies made playing it worth it.. (and I will get it from gog to do it all over again :))

Oh the days when I first got my hands on Fallout... at first I didn't quite know how to play(particularly because I'm not from english speaking country(Finland)) the game but I still enjoyed it a lot. After few years I got enough english knowledge to play the game properly and the game just kept feeling more and more fun.
And back then I always had slowest possible computer so installation was very much fun since I wanted to do "humongous installation" but I needed to clear almost everything except windows to have enough disk space :D
Week ago I just couldn't stop laughing about it when I installed Fallout again and looked the size of humongous installation...

The first Fallout. I remember that quite well, which is a feat since my memory sucks.
It was the last demo I got to install without approval from my dad. I was in a phase where I wanted to try everything, and so I installed it. Started out nice, you had a couple of weapons, and there where enemies around. So he is walking in as I am being attacked by a minigun wielding mutant. He just watch as I try to defeat this thing, but I didn't understand much, due to everything being English. Then all of a sudden, I explode into a bloody mess due to the mutants attack.
I just sit there, my dad just stares for a minute. Then I say: "I'll delete that demo right away"
His reply: "You do that".
Every time I looked at the cover for that demo CD, with the power armor helmet on, I wanted to play more of it :P

I didn't play any of the games on here when I was a kid, but I did play Age of Empires a lot.
And cheated. I still remember the E=MC2 code, and probably others if I tried really hard.