Shiny Buneary in Diamond, and shiny Purrloin in White. Both pretty early in the game. Had never run into one (legitimately *cough*Gameshark*cough* <_<) before that. And I've played Red*, Yellow*, Silver, Sapphire, Emerald, FireRed, LeafGreen, Diamond, and SoulSilver 100%. Still working on White1 / Black2.
*Didn't find shinies in these two for obvious reasons.
Paper Bowser can breath fire. While underwater. PSN: Fatal_Gear
Saw a pink Wooper in Silver version way back when it first came out but didn't have any pokeballs so I had to beat it, then I didn't see another shiny for 10 years. Finally saw a shiny Onix in Union Cave in HeartGold like 2 years ago and master ball'd it. It's now a Steelix named Rocksteady and is chilling in Unova in my Black 2 file, my only shiny.
Swablu, Tentacool (like 3 of them in different versions and I believe generations...), Sandshrew, (some more that I can't remember because they weren't that memorable for whatever reason) a Magikarp in Pearl and an Audino and a Boldore most recently.