TombRaider II
Level skip:
Step left, step right, step left, step back, step forward, turn around three times, do a forward jump and then immediately press the roll button to exit to the next level.
All weapons(not to mention the 40 extra health packs):
Step left, step right, step left, step back, step forward, turn around three times, do a backward jump and then immediately press the roll button to get all weapons and lots of ammo.