Nor have I, actually.
The closest I've come are something like 99% on Kirby: Nightmare in Dreamland; all possible star coins collected in NSMB (DS) but not having played the super-secret no-scrollback mode; and all items, upgrades, extras etc. bought / maxed out in Shovel Knight: Shovel of Hope and Shantae and the Pirate's Curse. The last two were by far the hardest.
But even I can't fathom how someone can 100% (or actually 103% even) the original DKC trilogy. It takes a godlike gaming talent to pull that off, I can tell you that.