It's difficult to pin down the 'best' because 'epic' means something different to everyone. For some, it's the sheer scale of the world-building. Others need that intimate character journey across continents. I find myself drifting back to authors like Robin Hobb more often than the usual doorstop-sized recommendations. 'The Farseer Trilogy' might not have armies clashing on every page, but the emotional weight of Fitz's life feels more epic to me than any magical battle. The toll it takes is immense, and finishing those books left me genuinely drained in a way few others have.
That said, you can't talk about the genre without 'The Stormlight Archive'. The world is undeniably huge, with unique ecosystems and a deep, mysterious history. Sometimes the plotting can feel a bit mechanical, like Sanderson is checking boxes on a fantasy trope list, but the payoff when the pieces click is undeniably satisfying. It's a different kind of epic, one built on meticulous systems rather than raw feeling.