Die Hard -

Infinite Lives:
801D5930 0002

Die Hard 2 - Die Harder -

Infinite Energy:
800B95B0 0005

Unlimited Bullets (Note 1):
801FA0F6 000F

Die Hard With A Vengeance -

Infinite Time:
800D87FC 4E80

Note 1 - This code will give you unlimited bullets with any weapon selected & no need to reload.