God mode in Doom II. Can’t remember it right now, but I do remember the sweet feeling of being able to punch cacodemons to death. Ah, omnipotence…
OH, wait, here it is:
type IDKFA for all the ammo and all the weapons.
Type IDDQD to be invincible.
Sweet!
“radio free zerg”. It only works in single-player when you’re playing as Zerg, though.
The Starcraft invulnerability code is “power overwhelming”, one of the quotes the Archon says in the game, and the code to skip to the next level is “there is no cow level”, a reference to Blizzard’s other game line, Diablo (in the original Diablo, there was a (false) rumor that they just couldn’t kill that there was a secret Easter egg cow level. In the DII expansion, they finally broke down and actually put in a real cow level).
In Rise of the Triad, I seem to remember that entering the code for god mode gave you as your armed weapon a hand that shot lightning bolts. You also made some sort of goofy “dohh?” sound as you walked around.
In the same game, I think there was a code that would give yoiu “dog” mode.
RR
Damn message board ate my first post. Wish it would stop randomly logging me off…
Anyway, even though I hated the first Age of Empires, it had some great cheats. One of them (you had to type in “protonman” I believe) summoned a futuristic storm trooper guy with a laser rifle who would fight for you. Another one (“bigdaddy” IIRC) summoned a cool-ass black corvette with a rocket launcher on top. It was great fun roaring around and blasting villagers with it.
Shadow Warrior had a cheat which would make your rocket launcher shoot out heat seeking, pissed off, carnivorous bunnies.
Hexen and Heretic both had modes that could change you into harmless farm animals and would also adjust the view point to reflect that you were very short, along with an appropriate weapon, such as a beak or a snout. Hexen had a pig, Heretic had a chicken. Great fun…
The original Blood had a code (“hongkong”, if I’m not mistaken) that would give you unlimited ammo and all weapons. Combine that with god mode (don’t rememeber that one), and you could go to town killing everything with a can of hairspray and a lighter. 
And the sequel has a Cobra! I think the code is, “How do you turn this on?”
Civ 1: !@#$%^&*()T will cause the version I have to display the entire world.
Carmageddon 3: I would never have finished the game if I hadn’t found the code to freeze the timer.
Of course, giving Brother Wu more than you actually owed him would made you a trillionaire in no time.
GTA3’s tank code is sweet. But my new favorite is the “blow up all cars” cheat. I like to put in every button but the last one, slowly walk away from an intersection, and push the final button. BOOM!
That’s probably the coolest effect, but I think my favorite name for a code was the God code for Duke Nukem 3D-- DNCORNHOLIO.
Oddly enough, one of my favorite cheats comes from a game I’ve never played…SimCopter, the Maxis made flight simulator that let you use SimCity 2000 cities as templates for the cities you flew (civil) missions in. Though, from what I remember, it had the weakness of being somewhat underpowered for a good flight simulator…
"Egg Title : Apache attack-chopper
How to crack it:
- Press Ctrl-Alt-X, then type I’m the CEO of McDonnell Douglas.
- Go to the hangar where you purchase helicopters and press 3.
- Go outside and check it out–a brand-new Apache attack-chopper awaits you. And it can even fire missiles!"
…It just sounds so COMPLETELY cool. I always wanted to try that out on a replica of Disneyland I had built in SimCity. >:)
Ranchoth
You guys still haven’t gotten the Konami code (Contra version) right yet! It’s Up Up Down Down Left Right Left Right A B A B Select Start. My friend just broke out his (brand new looking and still in the original packaging) old-school nintendo about two weeks ago we beat contra
Oh and:
I’ve never forgotton that because my dad actually carved it into my game with an exacto-knife lol.
“cockadoodledoo” was the code in Hexen to turn yourself into a chicken. I never could find the one to turn yourself into a piggy though. That was my favorite thing to do to my friends who hadn’t played before. Watching them scream “What the fuck?” as all their weapons dissapear just as a huge Hell Demon of Whoop Ass comes out. Nice.
And how come no one’s mentioned “Justin Bailey” from Metroid? Makes big ol’ Samus run around in nothing but a one piece bathing suit. And if you win, she flashes you a bikini 
(ahh, the joys of early pubescent adolesence).
And of course, Destroy All Monsters for Nintendo’s Godzilla allowed you to fight all the monsters on stage one. It’s actually rather upsetting to essentially beat the game, then have to go to stage 2.
If only I could remember the game… it was a platformer of some sort, I’m sure… anyway typing in ‘Steve Austin’ would switch to sloooo-mo mode!
In a few of the later games they changed the konami code where ya had to do it backwards
But if ya did it as normal you instantly died
Ironically cheat codes started as a way for the game testers to test the game and not worry about dying and the like
Now Its a must to have one or 2 in a game now
But in console games hidden codes have been suprassed by the game genie or game shark as its now called in the us everywhere else its called pro action replay
Of course theres flaws with it but on the whole it works pretty good
Mine was in Civ I–the shift-1-2-3-4-5-6-7-8 cheat. Used to spy on your enemies’ cities, see the whole map, sell their city walls just prior to attack, and so on.
Also, you could see how the dang computer cheated like heck. Triremes sailing merrily across vast oceans with no shore in sight my hiney!
Tomb Raider 2 on Playstation: During the game, have Lara step forward, step back, spin completely around three times while holding down the walk button, and then jump backwards.
Hehehe:D
Quoth slortar:
A common, but potentially deadly, mistake: Them animals were not harmless. The first time I ever played Hexen multiplayer, I got turned into a pig (by the legitimate item, not the cheat code). While my opponent stood there gloating, I snouted him to death.
By the way, I think that the code for “pig mode” on yourself was “redemption”, but I might be misremembering that one. There were also a few ways to legitimately get pig mode in single-player.
Now this is why I don’t use cheat codes.
Using just skill, I landed on Alpha Centauri in 1500 BC.
I will always remember the justin fisher code for Metroid on NES.
I was a little kid then but it was the easiest to remember because there was a kid at my school named Justin Fisher.
Ummm, wasn’t it Justin Bailey? I’ve always rememered because there was a kid at my school named Justin Bailey.