Mine is with using the pokeradar- I was chaining Abra on the route East of Jubilife city, and ran into a timebomb patch (that is where you encounter a wild pokemon that is exactly what you are chaining, yet for some reason breaks your chain). The abra that came out of the grass was shiny, with the normal 1/8192 chance of being shiny. The patch even looked normal.

Umm...action replay XD

It was in SoulSilver. I was in Belsprout Tower at night, I ran randomly into a shiny Gastly. I caught it. I did a pic for it. Now shes a Gengar. We almost dont see that shes shiny. SHINY GASTLY ARE SO COOOOOL!!!!

I know its hard to belive but I got two evaloshins of the same pokemon shiny I coght a shiny Rosezilya and evolved it in to Roserade and not long after I coght a shiny Beduw and I have alot more shiny pokemon but thats my oddest encounter well that and catching a shiny Aduno on new years day.

shiny zigzagoon in my sapphire while looking for surskit. (my only shiny, crying face)