I have never caught any shiny Pokemon that I have specifically been hunting, but I have however captured: Shiny Gyarados, Shiny Nidoran (Female), Shiny Voltorb, and a Shiny Slowpoke.

All have reached their highest evolution, Slowpoke becoming a Slowking.

I've never really put in the effort for hunting a shiny Pokemon, but that's really because I recall reading that they actually, in most cases, have poorer base stats than those of the regular variety.