There hasn't really been a unified thread for this, so I will take the liberty to create a thread dedicated to compiling and organizing friend codes/gamertags for the various next-gen consoles. Simply post your friend code or gamertag in this thread (along with game if it is a DS game), or alternatively PM it to me, and I'll keep a tally in the original post.
PSN ID:
Adam: argonwow
azn099: azn099
Baiko Arashi: Billy62289
Davey Vengeance: kurenaiOD
Dong Zhou: magic-hat1
Elitemsh: Elitemsh
Foif: Vexterra
hall_of_famer02: hall_of_famer02
Kong Wen: KongWen
LittleDragonZ: LittleDragonZ
Marc: tehmarcerer
Master Still Water: Janky_Toe
Mikhail: la_Boomstick
mrbeate: LtElric
Omega52: Omega52
SlickSlicer: YuanShu
SunXia: Sunxia
talon1579: talon1579
Tan_Binrui: IgnatzVII/Ignatz VII [???]
Tiger of Kai: leakbrewergator
Zhao Yun of Changshan: Heck-tic
Steam
Adam: http://steamcommunity.com/id/argonwow
Bryan: http://steamcommunity.com/id/drauks
Kong Wen: http://steamcommunity.com/id/kongwen
Marc: http://steamcommunity.com/id/xayun
Qu Hui: http://steamcommunity.com/id/caesar_pollux
Ranbir: http://steamcommunity.com/id/teamranbir
Wii:
James: 8205 2237 8168 6977
Kong Wen: 3529 2738 6113 2063
Liu Yuante: 6205 1243 8588 1935
Mikhail: 1660 3845 7540 9790
Omega52: 5602 6757 6572 2778
XBOX 360:
Bryan: Ashes of Atma
Cao Hong: fidi reel
dymlos timbre: TIBERIUM89
EmperorWu: TheEmperorWu
Exar Kun: HandofExar
Faerlyte: Faerlyte
Jason: JBird3387
Jeremy: NoCider
Justin: lechems
Kong Wen: Kong Wen
LiuBeiwasGreat: Atom523
Lu Kuang: Aidan17
Marc: tehmarcerer
Mikhail: Boomstick Redux
Ranbir: Team Ranbir
Seperation Anxiety: Crazyfool318
Shikanosuke: II Budtron II
silver.waterlily: Silverwaterlily
Sun Gongli: Bofubutt
Tan_Binrui: Tan Binrui
TheRealWolfman: The Bhrama Bull
WuLordoftheNewAge: Ds1nt3k13666
DS Game Codes:
Animal Crossing: Wild World
Ranbir: 1675 9609 6616
Castlevania: Portrait of Ruin
Aquinas: 4596 4735 8427
Final Fantasy III
Aquinas: 4081 0606 2858
Ezekiel: 1418 3413 9998
Jump Ultimate Stars!
Ranbir: 5326 6806 8474
Pokemon Diamond/Pearl
Aquinas: 1203 5689 6868 [Diamond]
Ezekiel: 0387 5355 7331 [D.] / 4897 2553 5334 [P.]
James: 2965 0212 5741 [Pearl]
Lion's Mane: 0473 4586 9539 [Diamond]
Ranbir: 5369 7992 6866 [Diamond]
Rhiannon: 4124 1634 7421 [Pearl]
Pokemon Platinum
Jason: 4769 3618 4276
SPORE
Aquinas
Ranbir
Marc
Niahak
James
Mod Edit(SX):Updated list 16-10-11