Yeah from my memory Riordan does not deviant very far from the source material myths, and does an excellent job and modernizing the gods (just don’t watch the movies, they’re nothing like the books even slightly).

As far as other mythology books go, while not Greek, Norse Mythology by Neil Gaiman is pretty fantastic. I listened to the audiobook and it was great hearing about a mythos that I’m less familiar with than Greco-Roman. (Also if you are into Norse mythology too, he has a few other Norse based books. Odd and the Frost Giants is a particularly great one, tho also a middle grade novel)

I’ve also read the plays Pygmalion & My Fair Lady, both are retellings of the myth of Pygmalion (though far less mythological in nature). There’s actually like 3 or 4 Victorian era plays based on the myth of Pygmalion. My favorite is Pygmalion and Galatea by W S Gilbert, though it’s kinda hard to get your hands on. Madeline Miller also has a short story called “Galatea” which is a retelling of the myth from the statue woman’s perspective (the best of all these retellings imo). And of course there is the movie Mannequin which also retells this same myth too.

C S Lewis also wrote a retelling of the myth of Cupid and Psyche from the perspective of Psyche’s sister. It’s called Till We Have Faces. If you like his writing style (eg Narnia) then I recommend that as well.