On Steam, I've made a mess of things that I should clean someday.
It's categorized mostly by purchase time. I have folders like Summer Sale 2016, Winter 2018, Beated 2018, New Games (containing games from like 2013-14), Currently Playing, Currently Post-Game, and various others like that, as well as bundles together (Tomb Raider, Spiderweb Software, Humble Bundle)
For physical, I used to try to organize my N64 and GCN/Wii, but never had much space. It's been... mmm. It's been about fifteen to twenty games I want to play/"am playing"/would play again in a drawer by the console, and the rest either in another drawer or in my room. Not actually sure where my N64 stuff is atm either...
"In my headcanon, some staffer saw Trump pull out his phone and start typing so they just Terry Tate Office Linebacker'd him out of his shoes." - FFD