>>30475267up to gen V, none (excluding the scripted gyarados)
gen VI, I encountered 19 total, 16 of which I caught.
first shiny was when I was horde-farming scyther in Y. got a shiny swablu. I'm pretty happy with it.
also got electrike, sandshrew and zubat from hordes, though the zubat was while I was EV training.
dexnaved a numel in OR just before the elite 4.
randomly encountered a metapod in Y.
Masuda method'd a furfrou, two froakie, three ralts (2 female, 1 male), a shinx and a pachirisu in gen VI.
had a fun time with shuppet. I found one randomly while EV training with hordes, but all my moves were either normal or multi-target (so no way to kill the others off) I eventually watched it struggle itself to death.
naturally, I was a tad unhappy with this outcome. so I swapped out double edge on my venusaur for energy ball, and horde farmed for two days until I found a replacement.
I also accidentally killed another shiny shuppet while EV training shortly before SM came out, so my overall record is 1 for 3.
in SM, I chained a shiny rockruff between akala and ula'ula islands (story wise)
I've since beaten the game, and am now 800 eggs into a shiny mimikyu attempt.