I'm not really good with the shiny thing but eh, I'll give it a go
My first shiny was a shiny tympole: Random encount
Game: White 1
This shiny made me surprized I jumped screaming " A SHINY RANDOM ENCOUNTER OF TYMPOLE OMG OMG OMG OMG!!!" It was level 13 and I just threw and ultra ball and it got caught, I was so surprized! Its weird how I didnt level it up and use it as a main pokemon :/
Now its in pokemon Black 2 and a shiny semitoad, Trying to get shiny tympole again, hatching from an egg, hope this method works...
Number 2: Shiny gible: Pokemon black 2
I found this 1 after black tower, It took me 1/2/3 days to complete black tower, this includes getting out of the tower later and do whatever,level stuff up and go back.
I went to alders house and found this little beauty at level 1 from Alders grandson, Id rather the shiny dratini than this shiny gible as shiny dratini looks better,evolves into dragonair and dragonate, and they look EPIC in shiny mode, with this gible, its useless evolving it, yea gabite is cool but I'll breed my shiny gible (Thats my method if I need another that you can only get once in the game)
Now Pokemon Soul silver RED GYARDOUS: This fella was not tough at all, use an ultra ball or 3 and bam caught at full health (I go ultra balls when I find legends at full health or plain old shinys either way) But the shiny Gyarous, was part of the game, and you needed to encounter it to go on in the game (like with sudowoodo, my best bud for a few badges and he appeared in my PC and was a strength slave from then on now Ho-oh does that job with Gyardous) I got heart-broken...
And i only used gyardous to beat up some weak gym badges and wild encounters or just a plain old healer and let Ferligater do the work.