Alright, so I've probably gone overboard trying to read a bunch of partial series over the years. It's a different kind of commitment than starting a finished one. You're basically signing up for the waiting game. My top recommendation, if you want to ease into it, would be Tamsyn Muir's 'The Locked Tomb' series. It's got two books out with more coming, and the thing is, each book feels like its own complete, wild experience. 'Gideon the Ninth' is a self-contained puzzle-box of a novel with a satisfying conclusion, even though bigger mysteries loom. It leaves you desperate for the next one, but not because you were cheated out of an ending—it's because you're just so dang invested in the characters and the world she's built. The sheer stylistic whiplash between the first and second book ('Harrow the Ninth') proves she's not just repeating a formula, which gives me a lot of confidence in the unfinished future.
For a totally different vibe, I'd point you toward N.K. Jemisin's 'Great Cities' duology (so far). 'The City We Became' and 'The World We Make' are incredible, and they function almost as one big story split in two. Because it's a duology, you're not facing a ten-book marathon of waiting. Jemisin is a master world-builder, and the contemporary fantasy setting feels urgent and alive. Starting with a series that the author has signaled is shorter, even if not complete, feels like a safer bet than diving into some sprawling, decade-long epic where the author's pace has slowed. These books are recent, brilliant, and the wait for whatever she does next in that world feels manageable.