Oh, if you haven't read Ancillary Justice and so forth, that is excellent!

Yeah, I was going to rec Ancillary Justice.

There are all the old SF books from the 60s/70s, like the Rama books etc. I haven't read them since I was a kid so I don't know how they hold up.

Oh! Empress of Forever by Max Gladstone. It's less on the hard science and more on the quantum, sort of Guardians of the Galaxy meet Godel Escher Bach.

The Ancillary novels are great. Although somehow I missed that everyone was referred to with female pronouns until the 2nd book i think. I just assumed there were only women. Once I figured it out I went back and reread and some things made more sense.

The last sci fi series I really got into was Tanya Huff's Valor Series.

Although the stories are different there are similarities with mystery aliens and well written characters (esp female characters) and..well...space.

I'll look up the other recommendations and see what I can get my hands on.

Guardians of the Galaxy meet Godel Escher Bach.

Well, fine, I guess I will have to read that, then.

had recommendations for sci fi series that would be along the same vein

I highly recommend the Chanur series by CJ Cherryh. They're a bit old, but they're fun: a multi-species interstellar economic compact is thrown into political chaos when a single human shows up from outside their territory. The main character is a female feline ship captain, who finds humans entirely unattractive, and thinks males are inherently unstable and violent. She's a total badass.

Four novels, so much shorter than Cherryh's recent stuff, told entirely from non-human POV. Lots of chases through space, battles in space and on planets and space stations, strategy and politics, alien psychology, and so forth. Great stuff. Look for The Pride of Chanur, which is the first in the sequence.

I'm currently half way through Harrow's The Once and Future Witches. It is engaging and I am enjoying it, but I don't love it to the level I loved The Ten Thousand Doors of January, but really that is a very high bar.

I'm putting the Chanur series next on my list as that sounds like my jam. And I do prefer a series. Looks like 5 in the series.

Seconding the Chanur books, and pretty much anything by Cherryh.

Cherryh is really good with aliens, making them actually alien and not just humans in costume. Chanur and Foreigner are my favorites of hers.

I saw that the author of "The Phantom Tollbooth" has died. I think it came along when I was too old to be part of the target audience, but I saw that he'd died.

No one is too old for The Phantom Tollbooth!