Thumbs up for The Song of Achilles by Madeline Miller. Historical fiction.
Weirdly, I've never actually read the Illiad (or not all of it, anyway) but since my interest in the Greeks was originally piqued by reading The Firebrand and the The Odyssey at an impressionable age, I am intimately familiar with the story. The Song of Achilles is not, however, just the story of the Trojan War retold; it is about the lifelong love of Achilles and Patroclus (which requires a couple of brave authorial decisions I think Miller pulled off beautifully, but I can't comment without spoilers). At first I thought the writing was rather basic; then I realized it was deceptively so: that kind of simple pure prose in which the smallest twist can be devastating. I was also impressed that Miller never jolted me with an off-kilter historical detail. When, after I was done with the book, I read in her bio that she teaches Latin and Ancient Greek at Brown University, I was conversely impressed that never once did her scholarly expertise interfere with her gorgeous storytelling. Yes, The Song of Achilles is, in base terms, Homeric slash fanfic; but it's a thing of beauty. Highly recommended if you're looking for something about the Ancient Greeks, tender GLBT romance, or just a lovely novel to lose yourself in.
I turned. Thetis stood at the edge of the clearing, her bone-white skin and black hair bright as slashes of lightning. The dress she wore clung close to her body and shimmered like fish-scale. My breath died in my throat.