Master ball cheats for any pokemon game?

Action Replay Code:

999 Master Balls in Bag (Press L + R)

94000130 FCFF0000

B21C4D28 00000000

BOOOOOO4 00000000

00000F4C 03E70001

D2000000 00000000

This code will give you +999 Master Balls in Ball Bag Slot 1 (Press L+R), however keep note that if it doesn't work for your Pokemon Diamond it may be only for Pearl or vice versa.

TRAINER TIP: A lot of people make the mistake of using the the Master Ball on Dialga/Palkia or other difficult Pokemon. I instead recommend using a Quick Ball immediately.