Doom

IDDQD - God mode
IDKFA - All weapons and keys
A - Gives you a computer automap
IDCLEV followed by a number will warp you to a different level.
IDFA - All weapons (no keys)
MDT - Shows complete map (doing it twice will also show you the enemies)
IDCLIP - No clipping mode (walk through walls)
IDSPISPOPD - No clipping mode (try it if OUP doesn't work)
IDBEHOLD followed by one of these letters:
I - Makes you invisible
L - Switch on all lights
V - Makes you invulnerable for a few seconds
R - Gives you a radiation suit
S - Gives you a berserk pack

IDDQD GOD MODE

Sin usar claves, trucos y sin recurrir a guardar partida en cada esquina