Tekken 2

Accessing Sub Bosses:
Just beat the game with a normal character to gain control of their mid-boss.
Accessing Kazuya:
After all the mid-bosses are selectable, beat the game with any one of them to gain access to Kazuya.
Accessing Devil:
To access Devil Kazuya, just beat the game with Kazuya after he has become selectable.
Accessing Alex/Roger:
To access Alex and Roger you must win in the third round of your third match with less than 5% on your energy bar left. If you do it correctly you will hear the announcer say "Great" and your next opponent will be Alex or Roger. Simply beat them and the next time you go to the character select screen, they will be selectable.
You MUST have access to all the characters before the codes listed below will work.
Kazuya's Purple suit:
Hold start while selecting him from the character select screens.
Big Head Code:
Simply hold select while choosing your character in any mode.
SD Mode (or bigger heads):
Hold select while choosing your character AFTER you have already performed the Big Head code.
First person perspective:
Hold L1 and R1 while selecting your character. Only works in one player modes.
Second person perspective:
Hold L1 and R1 on controller 2 while selecting your character. Only works in practice mode.
Super Juggle Mode:
Hold U and "Select" on the opposite controller you will be playing on while choosing YOUR character. If you do the code on your controller then YOU will be the one being juggled high.

Theme Park

Money Code Enter as your nickname BOVINE and press O + [] + X during game (Can be done more than once).

Tomb Raider

Level Skip:
Enter the inventory screen by pressing Select, and press the following buttonsand press L2, R2, L1, 0, /\, L1, R2, L2.

All Weapons & Maximum Ammo:
Enter the inventory screen and press the following buttons:
L1, /\, R2, L2, L2, R2, O, L1 (for the NTSC version)
L1, /\, L2, R2, R2, L2, O, L1 (for the PAL version)
You should hear now a sigh confirming the code, then exit and re-enter the inventory screen. You must be using joypad configuration #1 for the code.

Total NBA '96

All Star Game:
When on the Exhibition Game screen hit the following buttons:
R1, L1, R1, L1, R2, L2, R2, L2 for the ALL STAR game 1
OR R1, R1, R2, R2, L1, L2, L1, L2 for the ALL STAR game 2

Tunnel B1

All weapons and Full Life:
Press L1+ R1+ L2 + R2 + [] + O + X + T all at the same time.

Twisted Metal

Codes: Enter these as level passwords:
Infinite Weapons: /\ _ [] O O
Unlimited Turbos: /\ X /\ /\ O
Helicopter: O O /\ X (only four)
Fight For Your Life: [] /\ O [] []
Fight Minion: /\ X O [] /\

Twisted Metal 2

Sweet Tooth:
at the character select screen press U, L1, /\, R quickly. You will hear a crunch sound. Now move over until you see Sweet Tooth.

Minion:
At the car select screen press L1, U, D, L.

Secret Tracks:
Jet Moto (at 2 player track select): U, D, R, R1.
Rooftops (at 2 player track select): U, L, R1, D.
Cyburbia: D, U, L1, R1.

Shield:
press U, U, R.

Napalm:
To activate Napalm press R, L, U.

Invisibility:
Press R, D, L, U.

Invincibility / infinite weapons:
Hold L1, L2, R1, R2 and press Up, Down, Left, Right, Right, Left, Down, Up.
You should see 99 turbos if the code was entered correctly.

Passwords:
Moscow: _ /\ X X X _
Paris: _ X /\ [] X /\
Amazonia: /\ _ _ _ X O
New York: /\ /\ X /\ X X