I was looking all over the internet and couldn't find any good cheat codes for pokemon diamond or pearl. (these don't work if you don't have action replay.)
Here are some that I think would be useful for pokemon diamond/pearl. Also if you have any good codes for pokemon diamond/pearl or any other game please help someone out by posting them.
press L+r while in the game to activate these
Rare Candy x999
94000130 fcff0000
b21c4d28 00000000
b0000004 00000000
00000dac 03e70032
d2000000 00000000
Master Ball x999
94000130 fcff0000
b21c4d28 00000000
b0000004 00000000
00000f4c 03e70001
d2000000 00000000
Pokedex 100% Complete (L+R+SELECT)
94000130 fcfb0000
b21c4d28 00000000
b0000004 00000000
e000154c 00000124
ffffffff ffffffff
ffffffff ffffffff
ffffffff ffffffff
ffffffff ffffffff
ffffffff ffffffff
ffffffff ffffffff
ffffffff ffffffff
ffffffff f0001fff
ffffffff ffffffff
ffffffff ffffffff
ffffffff ffffffff
ffffffff ffffffff
ffffffff ffffffff
ffffffff ffffffff
ffffffff ffffffff
ffffffff ff001fff
70000000 00000000
00000000 08050000
00000000 00000000
00000000 00032000
00000000 02000000
00000000 08000000
80000000 00800000
20000000 00000080
7fffffff fffffffc
ffffffff 7ffff9ff
ffffffff ffffffff
ffffffff ffffe7ff
ffffffff feffffff
ffffffff efffffff
dfffffff ffffffff
fbffffff 00ffffff
00000000 f0f0ffff
03020100 07060504
0b0a0908 0f0e0d0c
13121110 17161514
1b1a1918 00000000
d2000000 00000000
Max Cash (Press L+R)
94000130 fcff0000
b21c4d28 00000000
b0000004 00000000
000002e4 000f423f
d2000000 00000000
Wild Pokemon Modifier
94000130 FDFF0000
B21C4D28 00000000
B0000004 00000000
94000130 FEFF0000
00000890 01ED0001
D0000000 00000000
DA000000 00000892
DC000000 00024620
C0000000 0000000B
D7000000 00000000
DC000000 00000006
D2000000 00000000

1. Press L+R at the inventory screen, then you'll get 493 Masterballs in your first item slot.
2. Set decrease the number of master balls so it matches the pokemon number in the national dex.(Example: Mew=Pokemon number 151, discard until you have 151 Master balls)
3. Hold L while in the grass and encounter the Pokemon that you want. DO NOT push L+R together again or you will have 493 Masterballs again (unless you want Arceus as his Pokemon number is 493)

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For those of you that are waiting for more codes I will post more later.

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friends, family anime books and most importantly THE JONAS BROTHERS

could you mabye post a cheat code for mario kart?

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ive got a cheat for mario kart!
while ur waiting for the track to load, hold down select and u end up with SHY GUY as ur driver!!