Steam

Man, calling them "backlogs" seems like a very unhealthy way of thinking about it. They're games you play for fun and enjoyment, not work you're behind on.

My categories are: Games I shall play one day: just all the games I haven't given a fair shake yet and would like to get around to at some point.

Games I am playing: games that I am actively playing, usually with some activity within the last month

Games I am done with: games I no longer want to play for whatever reason. Used to be "Games I have completed" but that didn't make much sense with multiplayer games or roguelikes, and it worked better for games I hadn't completed and just could not be arsed to complete.

Free games: games I have gotten for free and so have no plans to play.

Also have one for online multiplayer games and one for local multiplayer for when friends want to play something

Most of the time tho I just use the sort by recent and only installed bittons since those are the games I want to see anyway