Quake II: Ground Zero 
GT Interactive
Access the console using the ~ (tilde) key and type in the following items with the 'give' command.
ChainFist 
ETF Rifle 
Plasma Beam 
Prox Launcher 
Tesla 
Double Damage 
Hunter Sphere 
Defender Sphere 
Vengeance Sphere 
A-M Bomb 
IR Goggles 
Doppleganger
Flechettes [ammo for ETF Rifle] 
Prox [ammo for Prox Launcher]