Amazing games you wont forget

I forget everything :c

Bastion and Braid would be my top two choices. Half-Life 2 and Kingdom Hearts (1) are good runner-ups, though.
Edit: Also Gravity Rush. Amazing game.

Which genre? era? etc... I mean I'll never forget Super Mario Bro.s and Halo but for completely different reasons.

Bad Rats,Fortix 2:electric boogaloo and Dota 2.

007 Nightfire (Console version, use an emulator if you dont have a console preferably the gamecube version because ps2 version runs shitty)

Portal 2. A modern classic in my opinion. PLay it if you haven't yet.

Ultima Online. I miss the good old days.

S.P.A.Z

Knights of Honor, Rome Total War, Evil Genius, Empire Total War, Star Ruler, Startopia, Port Royale 2. To name a few.

Mirrors Edge, because of it's distinctive uniqeness.
Bomberman (NES) Amazing game that I played tons of, and still love, even on other consoles.
Super Mario Bros 3. My youth.
Super Mario 64. IT's FRIKKIN' 3D! 3D!
Portal. Oh, look, a strange FPS. Oh my god, valve isn't totally overrated after all!
Scribblenauts (All). Imagine it, play it.
Batman Arkham Asylum. I always found Batman somewhat cool but third person games boring. I didn't expect much. I got tons!
Alan Wake. I do hate horror, but I really love this!
TRAUMA. What the fuck is this and how come I love it?!
Mario Kart 64, the best multiplayer game in History
Super Smash Bros Brawl. Nintendo managed to build the hype so perfectly with the Dojo (only to somewhat break it with the late release date) and the game never dissapointed me. ever.
Bioshock Nooo, Ryan!
Diablo II. The first (and only?) game I wasn't allowed to play.

PoP Trilogy

Tyrian

Day of the Tentacle, Monkey Island series

NES contra and battle toads

Goldeneye on the N64 and Diablo II.

Deus ex 1. Jesus christ Denton!

There are lots of games to say here actually but the most recent one I can say is The Walking Dead The Game by Telltale Games. If I could live 100 years, when I am about to die, I could remember the feelings I've felt at the end of the game like it was that day.

GTA sand undreas/ genral zero hour/need for speed most wanted/max payne/call of duty modern warfare 2

The Portal and Bioshock games.

Bastion, that I finished a few days ago and this game is wonderful.

And also Dishonored.

Binding of Isaac, Plants vs Zombies, Portal franchise, Half - Life, Alan Wake and Borderlands.

Quake Live it's a modern version of Quake 3 Arena, fast paced, so fun! Graphics are like watching a microwave heat things though...