Quake 4

Quake 4 cheat codes: 
Cheat mode:
Press the [Left Ctrl] + [Alt] + [~] during game play to display the
console window.

Whilst in game press the [`] key to bring down the ingame console.
You can edit this key by going to x:Program Filesid SoftwareQuake 4q4base
and opening the file 'Quake4Config'. Look for line bind "`" "toggleconsole"
and change "`" to the desired key (i.e. bind "~" "toggleconsole").

Now enter the following cheats to activate the corresponding cheat function:
god                   - God mode
noclip                - No clip
notarget              - Invisibility
freeze                - Freeze everything
give all              - All weapons and ammo
give ammo             - Full ammo
map [map name]        - Load a map (see the list below)
benchmark             - Game benchmark
com_drawfps 1         - Show FPS
aviDemo               - Saves a demo of your playing to an AVI movie file
gfxinfo               - Graphics card infomation
r_gamma [0-3]         - Set gamma level
r_brightness [number] - Set brightness level
s_volume_db [number]  - Set sound volume (default is 0)
s_showlevelmeter 1    - Toggle sound level display (use 0 to disable this code)
g_showprojectilepct 1 - Toggle hit % to HUD (use 0 to disable this code)
killmonsters          - Kill all monsters
kill                  - Suicide
quit                  - Quit game