Another source of nostalgia for me: http://www.youtube.com/watch?v=tLWVyqRYiaI

EDIT: And http://www.youtube.com/watch?v=IYAna6uapXM.

Ooh good question. I'd say there are a few.

From my first machine, the Amiga
Nebulus
Venus the Fly Trap
Paperboy
Fantasy World, Magic Land and Treasure Island Dizzy
Xenon

Getting a bit older, and onto the Atari
Monkey Island then Monkey Island 2
Cruise for a Corpse
Maniac Mansion

On the mega drive:
The Lion King
Aladdin
Mortal Kombat 2
Streets of Rage
Golden Axe
World Cup Italian '90
Sonic (1, 2, knuckles and, to an extent, 3D)
Echo The Dolphin
Jurassic Park Rampage Edition
Primal Rage
Road Rash and the much improved Road Rash 2

The SNES:
Super Mario All Stars collection, primarily 3, though I have memories of them all
Donkey Kong Country
Some game where you would turn into some sort of werewolf. Isometric, played co-op. Beast-something, I think.

Then getting older and into the mid-teens. Looking at the N64 and goldeneye, ocarina of time, that sort of thing. And PC games came along with Counter Strike and Conflict Freespace. At this point there gets too many to talk about and I'm sure that most of mine will be the same as most of yours.

I think of all of them, Monkey Island is the one that really sticks out, along with Cruise For A Corpse. I loved that game, even if I never finished it.

Probably pokemon red, and later gold. I couldn't tell you how many hours i spent on those damn games. Especially red where i caught 138/150, which was pretty impressive for a five year old

Ratchet and Clank, Grand Theft Auto and Packman: Adventures in time.

Probably Phantom Slayer, an early fps from about 30 years back; other than that, the usual 2D platform and side-scrollers of the day.

At the arcade it was Asteroids, Space Invaders and Defender. On my Commodore 64 I played Chuckie Egg and Impossible Mission a lot.

Seeing the posts about Hide and Seek made me think of Flaslight Tag...and poked eyes, the fights about "I got you, No you didn't".

Also, it was mentioned that it's fun to play H&S as an advlt...indeed. Played a great game H&S on a staff training with some other staff at their community house. The twist was that it incorporated Tag as well. Running around in multistory story house that had multiple additions so there wasn't a sensible floor plan was hilarious! (and only slightly dangerous). It also proved that comfort zones can shrink when there are only so many places to hide

Fallout 2, Dungeon Keeper, Starcraft, Populous: The Beginning, Little Big Adventure 2, Warcraft 2, Baldurs Gate 2, Deus Ex, Chrono Trigger, Age Of Empires, Jazz Jackrabbit, Pokemon Yellow, SWAT (2?) and Postal 2.
Man when I was young there were awesome games being produced, now a days I barely even care about mainstream titles, only games I look forward to now are the Kickstarter cRPG's, everything else is just "meh". But when I was young there were tons of great games developed, the ones I listed are just the ones I enjoyed the most but there are othes I also enjoyed very very much, like Battlefield or Halflife and even Crash Bandicoot.

... What happened?

That's not how I ment it, apologies if it looked that way.
Ofcourse I also played outside back then. I used to play hide and seek alot and I loved to go into the forests with my friends and pretend we were knights and all that.

Well, it is an amazing game.

Casuals.

Casuals are the DEVIL! Do I fit in now?

Myst, Settlers 2, Phantasmagoria.

Age of Empires 2
Fable 1/The Lost Chapters
Spider-Man(NGC)
Metroid Prime
Ocarina of Time
Star Wars: Knights of the old Republic
Star Wars: X-wing Alliance
Star Wars: Dark Forces 2: Jedi Knight
Morrowind

Jak and Daxter. I wasn't very young when I started playing it, but I miss it passionately.

the game that defined my early childhood was The Legend of Zelda Ocarina of Time. The first game I ever played was Mario Kart 64. Both games hold very fond memories for me.

I probably played OoT more than any other game throughout my childhood and teens. Each time I picked the game up I'd get just a little bit further than I did the last OoT cram I had. I couldn't get past the Deku Tree when I got it for my 7th birthday. I reached advlthood when I was 9. I got to the water temple in middle school, I got to the Shadow temple when I was a freshman in high school, and I finally beat the game completely two days after my 18th birthday in my senior year of high school. I guess I personally attribute a kind of symbolism of my childhood to that game because of how my progress increased as I matured as a person.

I envy you, apparently "playing" is frowned upon. I might be almost 21 but I still enjoy going on a swing during early morning walks in the park. I sure wouldn't mind playing paintball, going bowling or hell playing hide'n'seek but apparently that's not "cool" or "age appropriate" so most of the time my friends and I pass the time by playing video-games or watching movies. the more "hardcoe" people I hang out with only consider clubbing and going to night-clubs entertainment.

I used to play quite a bit of LEGO Races and LEGO Island 2. Sometime after I went on to games like Morrowind.

An Acorn Electron game called Dragon Slayer. It was made of ASCII characters. I've never found a ROM of it or seen anyone recreate it. I really miss it!

Oh man, LEGO Racers, LEGO Racers 2 and LEGO Island were some of my favourite games back in the day too.

I especially liked freeing the brickster in LEGO Island, I always felt so accomplished when I managed to put him back in.

Lego Racer was a badass game indeed.

^^^ Chutes and Ladders was the bomb, it was my fave kiddie game. Candyland too.

I was a little too young for Pong, but when I was a bit older arcade stuff like Centipede/Asteroids/Space Invaders etc. are what the kids wanted to spend their quarters on. I did occasionally but I didn't have many quarters to spend when I was 9-11ish. So I read books (lots and lots and lots of books) or played board games with the family instead and then played Atari-home versions when dad bought one of those.

I tried turning on my Electron for the first time in decades a couple of weeks ago but it's not well. I also acquired a BBC Micro with a suspiciously CF-shaped "internal hard drive" with all sorts of software on it, I wonder if it might be lurking on there somewhere... I'll try to remember to take a look next time I use it, which should be before the 2020s.

Gah, I used to do that too with my neighborhood friends, all the time. At about 7 yrs old, running off into the woods with my friends. That was the early 90's.

You can't really do stuff like that anymore in today's world

Jazz Jackrabbit was an old favourite of mine too.