So I've been playing since R/B and I had never seen a shiny, but I recently was hatching Bagons and bang. Green Bagon. My first shiny. Then I'm in some friend safaris and I encounter a shiny Growlithe and Frogadier... After I had hatched over 500 eggs on a shiny Froakie hunt.
I've been playing since GSC (for about 12 years), and I've never gotten a shiny, until now. Got a shiny Ditto in Pokemon X's hidden garden three days ago. I was just about to start a chain using pokeradar, and this was the first one I got (so no higher chance to get one).
Funnily enough, a similar situation happened to me today. I was trying to catch Octillery for its suction cups ability in Azure bay to help with chain fishing. While trying to get one, I encountered and caught a shiny Corsola. (0 fishing chain so no increased chance on this one either)
3DS: 2406-6325-2795 Currently playing: Pokemon X, Xenoblade Chronicles, Bravely Default
Fracture in friend safari and I passed up on catching a noctowl in the pokemon village about two hours after that because I wasn't paying attention and i didn't even notice it was a shiny because it looks so similar to a regular still kicking my self
I'm gonna go with shiny Slugma in either Ruby or Sapphire. I know I saw a shiny Magnemite in Silver but I accidentally killed it with a Critical Hit Thief. And I know I also got a shiny Spearow in either Silver or Heart Gold but if it was Silver it was probably when I went back to that game after playing newer ones, and if it was Heart Gold it post-dates the Slugma anyway.
3DS FC: 1950-8925-0601. IGN - Michael Bug safari - Combee/Volbeat/Heracross