Hi all!
I’ve been reading quite a few worldbooks/setting guides recently, because I personally just enjoy that. So I was wondering if any of you have worlds/settings that you really like? Could be established TTRPG settings or just worlds from other media (books, videogames, etc.) that you really enjoy.
Looking forward to seeing what everyone’s into 
I think Shadowrun is probably going to top a lot of people’s lists. The original material was amazing. It got a bit weaker the more it defined things and introduced overly dragony backstory, and updating it to fit better with current tech was never a good idea, but wow, that initial stuff was fantastic. Such a simple Reese’s peanut butter idea, but so effective.
I also love the 1920s as used in Call of Cthulhu et al. Close enough to be similar to today, far enough away to be easily malleable and let us use whatever idealized version we choose, no tech to get in the way of spookiness. I’ve never been a huge Mythos fan, but the 20s are a joy to play in.
Single-planet SF like Blue Planet is also lots of fun. Way underused.
I grew up on “Aventuren” - the setting from the Dark Eye ttrpg - and love it. Shadowrun as H mentioned has a great setting (though I don’t enjoy the mechanics of the system).
Outside of ttrpgs I love the setting from the “Starship’s Mage” book series … most of it is “normal” space sci-fi, but travel between systems is impossible with technology and that is where the mages come in (obviously they can do more than “just” jump a ship between systems)
I recently started to enjoy a lot of Isekai and/or cultivation settings, "Batle Mage Farmer, “Beware of Chicken” and “Azarinth Healer” to name a few interesting variations - all of which are book series.
In terms of tabletop settings I am really enjoying Eberron. For me it has the right mixture of pulpy Indiana Jones fun, politics, and secret histories and conspiracies with many factions to tickle my fancy. I’ve run an investigation series in it, played two mini campaigns in it and wrote a second campaign in Karrnath (think militaristic country where necromancy is legal) and I’ve been having a lot of fun.
like Tersidian, I grew up rpg-wise in Aventurien as well,
… also I grew up in the World of Darkness alternate earth
so those two will always a have a spot in my heart
Shadowrun’s setting is also great, since mixing urban fantasy with cyberpunk is really neat
… speaking of terrible systems with great settings: Eclipse Phase is also worth mentioning
as is Hudson City for the Dark Champions rpg (HERO system; but the book is mostly systemless)
D&D-wise: Eberron is also really great, as is Tékumel, Planescape, and MtG’s Ravnica
scifi wise:
WEG Star Wars rpg has the Lords of the Expanse box for the Tapani sector
Star Trek Adventures has the excellent Shackleton Expanse book
lesser known ones include:
Semanawak from the New Fire rpg has also a very rich and beautiful setting
and, as mentioned by H, Poseidon, the planet from the Blue Planet rpg
as well as Tenra from the Tenra Bansho rpg
… and a have a soft spot for Candlewick Manor for the Monsters and Other Childish Things rpg (One-Roll Engine system)
… but my 
and fav. of all time is the City of Lies box set for the L5R rpg
describing Ryoko Owari Toshi in the country of Rokugan
… it is just sooo good …
Thanks for all the recommendations @H @Tersidian @BufoBufo @Darthbinks ! Some of these are definitely new to me, so I’ll check them out.
In the meantime, here are my own favorites:
I’ll throw in another “hell yeah” for Eberron - it does a excellent job of exploring the industrialization of magic, and just has so many interesting cultures/nations.
Valerna - the world of the fairly new Dragonbond family of games. It’s an extremely dragon-forward, very high-fantasy world with unique, vibrant takes on different fantasy races and monsters.
The Darkplane by Graham Ward. It’s a horror-fantasy setting with an awesome cosmology. I love the pantheon of this world, as well as the various planes of existence and how they affect reality at large.
The universe of The Magitech Chronicles, a bonkers space-fantasy book series with a really interesting magic system. There’s even a TTRPG for it now, which I wanna try out someday.
My favorite setting has to be Planescape - I’ve gotten a bunch of good campaigns out of it. Some of my favourite books have not been core Planescape - I liked Planebreaker, and A Fabled City of Brass a lot.
I like the Iron Kingdoms range as well - steam mechs, gator people, big, mad, techni-color fantasy - I would love to play that some day.
From non-RPGs I really liked the magical setting from the Crimson Empire books (A Crown for Cold Silver, etc.) with the bug-sting addicts, weird gods and magics.
Similarly for the Black Iron Legacy novels - Tallowmen, God-weapons, and service to your house beyond death itself - great stuff.
Like many other German-speaking players of a certain age I grew up playing DSA in Aventurien. Since it has made its impression on my then still malleable brain, it’s gods, history and magic feel to me like they have more weight to them than any other setting.
My current favorite has to be Spire. I love weird factions, gods/magic and conspiracies and Spire has lots of them.
Speaking of weird, Fallen London of the eponymous browser game, Sunless Sea an Sunless Skies is a setting I’d also love to run/play a game in.
Iron Kingdoms is also a setting I have wanted to run a game in for a long time. Still have the edition 3.5 books lying around.
there is more:
the tower-city of Spire from the rpg of the same name
I really like it … although note, that for some the setting can be too dark
Magnamund from the Lone Wolf (and Greystar) books series … there is also 2 rpgs in that setting (one a 3E product) … -H- dm-ed the nonD&D version once
Dunwall from the Dishonored games … there is also a rpg in that setting
plan to run a BitD-like 
unit game set in that setting one day
and how could I forget the island of Al Amarja from the surrealist Over the Edge rpg
the newest edition is a gem
once made a post for a game about it 
here
and there is the city of Itras form the freeform/imrpov-heavy Itras By rpg
just made a post about it here
@Darthbinks If you run something in Dunwall, I’d love to join. I thought of adding Dishonored to my post, but didn’t want to turn it into a list of settings I haven’t played.
Spire can be quite dark, yes, but I experienced that darkness more as gallows humor and the overall impression more as weird/absurd. Personally Shadowrun feels darker to me most of the times.