Zardnaar
Legend
I just purchased the new Midgard Worldbook (already have the first version) and it is great. Even if you don't run it, it has tons of great ideas. Midgard is a bit like fine wine: the more deeply I dive into it, the better it gets. I'd also recommend their Southlands book.
Tal'Dorei is also a nice setting book, but doesn't go into the same depth.
If you want something non-D&D to draw inspiration from, I highly recommend the very evocative Symbaroum game. The art is incredible and it is just so damn atmospheric.
Moving into SF, I also recently got the Coriolis game. Science fiction gaming seems to be having a bit of a renaissance and this is a gem.
I want the Midgard stuff + Tome of Beasts but Amazon and Bookdepository do not seem to have it. I want the Campaign setting, heroes handboook and ToB.
Where did you get yours from? Note I live in New Zealand so the discounts online help offset the postage costs.