Megaman X4

Unlock Ultimate Armor:
At the Character Selection screen highlight X and Press X, X and Left 6 times then hold L and Z buttons and press Start/Pause and hold L and Z until you enter the first stage then after the first stage go to the Jungle Level where the Leg Enhancement would be and Dr. Light gives you the Ultimate Armor with the Nova Strike unlimited.


Mega Man X5

Unlock X Ultimate Armor:
Go to the Character Select screen and highlight X then Press Up, Up and Down 9 times.

Unlock Black Zero:
Highlight Black Zero at the Character Select screen and press Down, Down and Up 9 times.


Mega Man X6

Unlock Night Shade Zero:
When you have unlocked Zero press L, L, L, R

Unlock Ultimate Armor X:
At the start press Left, Left, Left, Right