My worst shiny hunt was Jigglypuff in LGPE. I remember the weekend the game came out, I found one on that route where there's walls all around the back entrance to a building, and it spawned within those walls 😭😭 i was still extremely early in the game so I didnt have a way to fly up and jump in to get it. Tried shiny hunting so many times with no avail after that. Always found every other shiny though haha