foxworks: Glad to know I'm not the only one who maintains a spreadsheet for this or for that :p Take note, Sachys! lol
budejovice: I started out keeping key data for each game on index cards. The cards were color coded by genre. It was pretty sweet. But I ran out of steam around 150 games on my shelf. Need to get a spreadsheet up and running. :)
My spreadsheet includes game, vendor, original bundle the key came from if applicable, other vendor I also own the game from, whether I have the soundtrack, any associated serial number, and the URL if it was a direct-download purchase rather than through a storefront.
The games are also coloured-coded as to whether I have played/am playing them, have finished them, have played them before but not yet in this digital format, or if they are ones I should prioritise getting to.
I know it sounds like a lot, but it only takes a few seconds to add a new game or update a status, so it's a really help for very little effort.