If breeding counts then my onix/steelix :) if pokeradar counts, alakazam came before onix, I would have caught a shiny wingull back in ruby but I killed it not realizing what I'd just found at the time.
I think it was a shiny Zoobat. Or possibly a Golbat but I eventually evolved it into a Crobat with a little love. Its a light shade of magenta and is really good for a pokemon that is common(original form).
Madness? THIS IS SKYRIM!!!(kicks dragon into pit of death)
My first was a shiny Wurmple during the Bug-catching contest in Heart Gold (think it was after the Red Gyarados). The second was a Nuzleaf that I caught in the Nature Preserve in White 2, followed by an Audino in Black 2 that I caught on Route 5. I have yet to catch any shinies in either X or Y.