Cheat codes you will always remember.

[dogenzakaminion]

"bewareoblivionisathand" the unlock all cheats code for Turok 2: Seeds of Evil.

and "thereisnotry" the level skip code from Dark Forces 2.

Good times...

 

[thomeval]

Down, Down, Down, Right, Up, Up, Left - For a certain arcade dancing game.

 

[maninahat]

Age of Empires II:

Photon man
How do I turn this on?
etc.

 

[Sneeze]

A few that come to mind...

-The Konami code, obviously (even though I never played any Komani games, at all, I don't think )
-THESHIT, BSTARD and CHUFF from GTA1
-Motherlode and Rosebud from The Sims
-A bunch of "hidden" weapon combos from Twisted Metal 2 (Hold down machine gun and press ^ v ^ ^ ftw)
-ASNAED, VROCKPOKEY, JUMPJET and ROCKETMAN from GTA:SA on PC

I used to know loads by heart in PS1 days for a few of my games but they're gone now.

 

[GreigKM]

there is no cow level

 

[Drejer43]

Up up down down left right left right B A, of course.

It's crazy that so many people remember that.

Nah, not really that crazy.

Contra is older than me yet i still know of it.
As wolfy showed its a big meme.

 

[Thumper17]

R1, R2, L1, L2, left, down, right, up, left, down, right, up.
All weapons in GTA 3 and Vice City and first weapon set in San Andreas.


Red5
All weapons in Jedi Knights 2 dark forces.


SV_Cheats 1
enable console in valve games.

 

[John the Gamer]

gettherefast and thugstools

from GTA Vice City

Gives you a fast car and weapons respectivaly

 

[naab]

Up down left right square square square. Tenchu stealth assassins.

 

[Milenkov]

Q lab, from Nightfire for the Gamecube

 

[Vredesbyrd67]

MMLVSRM

Infinite ammo in Army Men: Sarge's Heroes.

NTC0394

Passcode for the downstairs palace security console in Resident Evil Code: Veronica. Also, WKD4496 is Claire Redfield's serial number in prison.

I have played A LOT of Code Veronica.

 

[Xaio30]

RIPAZHA!!

Flying cars galore in GTA San Andreas.

 

[Doowoo]

IDDQD
IDKFA

This ^

 

[Undead Dragon King]

Imperialentanglements & thatsnomoon- Star Wars: Galactic Battlegrounds

TIEDUP- Rogue Squadron

Somebodysetusupthebomb- Empire Earth

 

[jjofearth]

"marco" and "polo" cleared the fog of war on AoE II

 

[Ice Car]

Konami Code. I doubt anyone doesn't know and memorize the code.

 

[Jackle_666]

Medievil. A game about a walking corpse fighting other walking corpses. Forgotten what it does but:

Down, Up, Square, Triangle, Triangle, Circle, Down, Up, Square, Triangle

Put it together and what do you got?

DUST TO DUST. Genius.

 

[2xDouble]

*snip*

*snip2*

*snip3*

*snip4*

*snip5*

Spoiler: Sing it with me, Kids! *Cursing, NSFW*

 

[Professor Cubbage]

how do you turn this on
heese steak jimmy's
robin hood
lumberjack
rock on
and of course black death

 

[Lieju]

YPXXLVGE

The code for using items as many times as you like in Super Mario 3.

It's been 15 years, at least, since I used it. How on earth I remember that?