FreeSpace 2

During play, type www.freespace2.com  to open up cheats. You'll see a message to confirm. Now hold ~ and enter the following...
K                 Kill target
Shift + K         Kill targeted sub-system
Alt + K           10% damage to ship
Alt + Shift + K   10% damage to target
C                 Send message to enemies
Shift + C         Toggle countermeasure availability for all ships
I                 Invincibility
Shift + I         Invincibility for target
O                 Descent-style physics
W                 Unlimited weapons for your ship
Shift + W         Unlimited weapons for all ships
G                 All primary goals complete
Shift + G         All secondary goals complete
Alt + G           All bonus goals complete
9                 Move forward through secondary weapons
Shift + 9         Move backward through secondary weapons
0                 Move forward through primary weapons
Shift + 0         Move backward through secondary weapons
R                 Rearm request for target