The first non-scripted shiny I caught was Spinda while collecting ash for the flutes in Ruby or Sapphire.
The first non-scripted shiny I got was the Treecko (now a Sceptile) I received as my starter during one of my playthroughs of Ruby or Sapphire. It took me awhile to realise it was shiny and as result I thought there was something wrong with my game for awhile.
The only other non-scripted shiny that I've caught is a Beheeyem that I found while training my team up on Black.
Okay I'll bite. When you say non-scripted am I right in assuming you mean not hacked with an action replay? (I'll be honest I have done that once or twice)
Non-scripted meaning as in "randomly encountered". In other words, stuff OTHER than the Red Gyarados in G/S/C HG/SS, he's a scripted fight - you always encounter him on every playthrough.
Anyway, my first was an Unown 'I' on Gold. Had no idea what it was, and it ran away. Then several years later, a shiny Whismur on Ruby. After that, shiny Pikachu AND Rhydon in Diamond on the same day. (Then my copy got stolen... T_T) Finally, a shiny Emolga on White.(Why couldn't it have been a Golett??? :/ )
Yeah, I'm a Vocaloid fan. Problem? http://w11.zetaboards.com/TheQuittingReturner/index/