My first shiny was Dusclops...the issue being that I was in one of the Final Frontier challenges.
:'(
Although, when I was going through GTS in Pokemon Diamond, I found a shiny Deoxys that was a legit trade. I got it...problem is that the cartridge I have is...forgeted, but I still have the save data...or my friend does. I just need to copy it...and then I can see if I still have 'em.