So we got gamertags and psn

[Cyron Tanryoku]

But where the Nintendo IDs and 3DS Friend Codes (If they don't merge in the future)

[Blackheart521]

Always room under that face in your Sig

Though that would be nice to be added

[Volcompat321]

There's also the (severely outdated) thread in Off Topic, that I'll be updating in the very near future.
You can add it there, and also get others' friend codes.

PSN/360/Wii/DS/3DS/Steam/whateverothergaming codes&names could be.