A few novels for your consideration.
Ilium by Dan Simmons
This novel came up on several of my good-book searches, adored by amateur and professional lists alike. I hadn't tried it before now, since it seemed ponderous and sprawling and I wasn't sure I was ready for the commitment and effort it seemed to require, but dear God am I glad I gave it a chance.
The scope is indeed enormous, yet somehow not overwhelming. There are multiple stories going on, each chapter alternating between concurrent tales. Most are set in the far future, with one apparently in the far past, though the setting is apocryphal. One storyline follows a group of humans who exist on a nearly unrecognizable earth, in a post-literate time where human population is limited to 1 million, with each human granted a lifespan of 100 years (or five Twenties). All lifespans are lived out in full; anyone who dies reawakens in a new body, mercifully lacking the memories of death trauma. We follow a handful of humans driven by curiosity, seeking truth and answers to questions no one has asked in thousands of years.
Another story centers around a moravec, or a kind of android/AI that is a mix of organics and technology, who has a deep love and knowledge of the works of Shakespeare. Him and his companions (one particular moravec friend is a scholar of Proust) set out on a mission from their homes on the moons of Jupiter to investigate strange readings emitting from a mysteriously terraformed Mars.
The third and probably main story, though Simmons manages to make whichever one you are currently reading feel like the main plot, takes place during the Trojan War. The Greek gods are a combination of superhumans and super-technology, who regularly resurrect scholars of the Iliad from after their timeline to monitor the Trojan War and inform of them of any incongruities between the actual events and Homer's epic poem. The main character is Thomas Hockenberry, whose limited memories of his old life tell us he was once a Professor of Homer's works at Indiana University in our time. His existence is fascinating enough but then he becomes embroiled in the drama and duplicity of the gods themselves, being gifted by Aphrodite with special tools for the express mission of murdering Athena. Though it's a tough call, this may be my favorite plotline; the mix of ancient and classic events, modern sensibilities and brilliant, simple twists has proven insanely engrossing and exciting.
Many elements of this novel that initially resembled drawbacks immediately became assets. For instance, the depth and intricate factual information of the Iliad itself. Now, I've read Homer's poem a few times in my life, merely by completing a college education, and even once post-college as a civilian trying to look staggeringly intelligent to fellow subway commuters. Still my retention of every series of events and every character (akin to reciting a Dostoevsky cast) is poor, so I worried I was ill-equipped to enjoy and understand it to the fullest.
That fear proved unfounded. Hockenberry's insights become my own, and while I can't recite all the details of the Iliad like he can, I recognize almost everything he recounts and contemplates, and it's easy to follow his expert analysis. Additionally the impact of plot twists such as making love to Helen of Troy or seeing Achilles and Patrocles asleep, naked, and with an arm around each other, hits me with the same massive weight that occurs on occasion (even for me, no true scholar) when reading certain scintillating lines of the Iliad itself.
The other worry I had was about the technical language, the invented technologies and legitimate physics that are constantly discussed, specifically in the moravec-storyline. Simmons takes little time for unnecessary exposition, judging perfectly what I need to understand versus simply know and this 700 page masterpiece moves at the same clip as an engrossing young adult novel.
Not knowing how all the stories connect, though suspecting and receiving hints that they do, drives me on. The complete and convincing characters, full of humanity and struggling with conflict (men in divine situations, an android's adventure and emotion mimicking that of a classic Greek hero, a woman falling in love while all she knows about human existence is proven false) makes the next page too far away and the last page consumed too quickly.
*EFFUSIVELY AND HIGHLY RECOMMENDED*
Honorable Mention: The Scorpio Races by Maggie Stiefvater
This one was on a list of "If you liked Hunger Games, you'll like..." and it was really great. The female lead, Puck, is spirited and strong, vulnerable and fierce. Her counterpart, Sean Kendrick, taciturn and grave, magnetic and indomitable, provides a perfect counterpoint, and their two stories, intersecting and merging, evoke emotions like nobody's business.
Like Hunger Games, it is written in first person, and deals with challenges of identity enhanced by the life and death stakes of an inevitable conflict. Like Hunger Games the pace is pitch-perfect, the dangers real, and the reader becomes so invested in the characters and events that it is almost dizzying. Unlike Hunger Games, it is self-contained so while we can't stretch the enjoyment into sequels, it ends so honestly and completely that I am sure I'll read it again
Olmpyos by Dan Simmons, the sequel to Ilium, whose summary I won't let myself read until page 725 is under my belt.
Battle Royale by Koushun Takami, the cult-classic from the 1990s that many accused Suzanne Collins of ripping off, dealing with a fascistic government experiment pitting middle schoolers, alone on a island, in a fight to the death.
Even when I'm content an stimulated in my current book, there's always more to look forward to.