Installed
Gold games(good games)
Unnecessary(betas and that kind of thing)
Not Played
Platinum games(Best games imo)
Deleted(good, but worse than gold)
Awful(speaks for itself)

i think that Depressurizer would work nicely for you, it has an auto management for types of games as in RPG RTS Strategy etc

Favorites

To Review (for my review site)

Games

Local Coop
Local Versus
Online Coop
Online Versus

Works amazingly when you're looking to play with people and are out of ideas.

I leave things on favorite when I'm currently playing them with some frequency, or games I revisit a few times.

I don't.

I don't since they are already in alphabetical order, which is what I also do with physical copies of games.

Installed and Not Installed. Favorited the ones I use regularly. The search function is a great help though :)

publisher and or by genera

Library. Do you mean Steam games or books at the shelf on the wall? XD

i wanted to do that once, realized how much work it would be, and stopped immediately. xD

all i do is add all games i want to play to my favorites. so that category acts as my backlog, basically.

I organise by genre : FPS, str, rpg, puzzle, race, point'n click, mmo, etc...

I organize my library by genres. However I have left out many games because I'm not sure in which category to add them or because I simply don't have any other games in their genre so that I can create a new category. I'm even considering creating a category for all crappy games that I got for free in various sites.

100+ categories for 550+ games, made with Depressurizer in under 30 minutes:

1. Genre (Action RPG, RTS, Stealth action etc.)
2. Year of release (5 years by category, i.e. 1995-1999)
3. Setting (Cyberpunk, post-apocalypse, aliens, etc.)
4. Universe (Warhammer, Shadowrun, Star Wars, etc.)
5. Series (Hitman, Max Payne, The Witcher, etc.)
6. Features (mod, alpha/beta, remastered edition, FMV, etc.)
7. Alphabetical list.

Each game assigned to at least 3 categories (1, 2, 7), some - to more than 5 - always easy to find whatever I want.

Favorite
Hidden object <- it is too hard to remember which are they by their name
Tower defence

Installed
Finished
Must Play (bascially all games that i will play but have not installed yet)
Not finished (game i want to finish eventually but haven't played for quite some time for different reasons)
Maybe if too much time (all those extra games you get in bundles that you don't really care about one way or another)
Snack (games that you can play for 5-10 minutes, stuff like puzzle or racing games)
Old Version (stuff like wasteland 2 after they released the directors cut version, older version of football manager and so on)
Waiting for new episodes (episodic games where not all episodes have been released yet)
Trash (aka what is this even doing in my library)

Games I buy don't get categorized. Non-Steam games get put in one category, free-to-plays have their own category, and freebos from Gleam/Failmid have their own as well. If the Gleam game sucks but has cards, I put them in the "shit games to stall for cards" category. I also have a rewards category, where I put games I received as rewards (such as ones I get with coins from Tremor games, or other websites/apps). And of course, I have a special category for giveaways directly from people (when I win a game here on SG, a friend gives me a game, and the rare occasion that I get a free key before some ninja steals it).

Though, I usually use desktop icons to open a game. If you're interested in that, I have a little pattern on my desktop to organize it: on the right-hand side of my desktop, I place my games and music. On the first "row," I have four games/folders, followed by three on the second, then two, one, back up to two, then three, and finally four. I use folders for a game that's in a series (example: Star Wars games have their own folder, as do the Half-Life games, and the Postal games). Freebo games have their own folder too, and there's a folder for giveaway games. Surprisingly, my desktop isn't very cluttered and looks kinda nice.

Cons: Sometimes I forget which category I put a game in.
Pros: Everything else! It's generally really fast to find whatever game I'm looking for, and it's not too cluttered up q:

games played / games not played

Gifted / everything else.

girly games and ecchi in Hidden, rest in installed :)

Favorite and Shitloads

Some mayor genres (Action, rpg, fps, strategy,etc), multiplayers (mobas, mrpg, mfps,sandbox), f2p, early acces games, games without achivements, unfinished games (when some achievements are missing), finished games, and yesterday I added a new category: dead games (games without servers like Dead Island Epidemic and soon Nosgoth)

I just comment here to read later

I have actually started uninstalling games I won't play any longer, but that's the extend to which I organize ... guess I gonna need to do something about it in near future ....

favorites , finished , all games

My library is, up to down, then left to right: Law books; other science books; general literature; classic literature; kids session; others. I mainly pick only law books, however, so I think they should be organized between them, too. Good luck with organizing yours :)