My first shiny that I saw, and didn't really realize it was a shiny, I just remembered the sparkly star thing when it came up.
It was a trainer's Espeon in the Battle Frontier on Emeradl :/
But, I saw there was a duduo swarm on the first route of Pearl, so I decided to chain for a shiny one. When I hit a ten chain, I looked up before the grass moved, and, so I went to reset my Pokeradar, and I take a step to the left, and a shiny Doduo appears. I caught it, and named it Shinyduo.
I don't have that save anymore, but I have a level 2 shiny Doduo on Battle Revolution XD