Call of Duty 4: Modern Warfare (PC)
Enable the console from the game's in-game options. Hit the tilde key (~) to drop the dev-console. Type seta thereisacow 1337 and then hit 'Enter'.
Type spdevmap bog_a
and then hit 'Enter' again. This will start the game with cheats
enabled. When playing, drop down the dev-console and enter the
following codes (in bold) and press 'Enter' to activate or toggle them.
give all: Access all qeapons.
god: God mode.
noclip: No clipping mode.
ufo: No clipping mode.
notarget: Enemies ignore you.
give ammo: Full ammo.
jump_height #: Adjust Gravity (Default = 39).
timescale #: Adjust Time (Default = 1.00).
cg_LaserForceOn 1: Add laser sight to all weapons.
give <item>: Gives you an item. Put 'all' for all weapons.
demigod: God mode but your screen still shakes.
r_fullbright: Way easier to see things.
cg_drawGun: Get rid of your gun.
cg_fov: Lets you zoom with any gun.
Hint: Epilogue Mission
If you sit through the credits at the end of the game after beating it, there's one more mission available.
Unlock Arcade Mode and Cheats Option
After completing the game on any difficulty, these options should be automatically awarded to you: arcade mode and cheats menu.