Magic is one of my favorite things about a fantasy setting. You are not bound to the laws we know of and you can rewrite basic physics and reality to whatever you want. Also, building the world around it is extremely fun.
I like ping-pongs between harder and softer magic systems, but my favorite hard-leaning magic system has to be bending from Avatar. There are four elements, most people who can bend get one, and they can really stretch them out.
As for softer magic systems, I enjoy when it helps to make the world function. So far, I kind of enjoy the Owl House. Sure there are glyphs that harden it, but there are some branches like healing and construction that make it seem more like these magic covens are divided like labor guilds, rather than strictly element.
Malazan. The magic source is also a series of realms you can travel too. But also there are weird magicks that don't belong to the Warrens and spirit stuff. And learning about how the magic has changed over time along with cultures and religions.
It's interesting to read but it's not really a hard magic system, it seemed quite arbitrary to me at times.
Then again I never did finish the series, maybe it ties up more nicely towards the end.
Malazan is a book series where you never have all the information as a reader. I haven't finished yet either, on book 7 currently, but you get dripfed lore about the origins of the Warrens and the depth within them. I have also been told that the ending is very nice, the last few books in general. If you enjoyed it, I'd give the rest of the books a shot.
Would also recommend Tor Reread of the Fallen to catch you up on the last books. It's very helpful for catching things that were easy to miss or forget.