Insta-rec - long Star Wars fanfic series

Ouroboros by bedlamsbard, is set before the end of the prequel films, around the time of the Clone Wars - but don't worry if you don't know all the wider universe of Star Wars - I came in as a casual fan, who's seen all the films but not much more, and didn't have any trouble following the storyline.

A Sith artefact drags our heroes (Obi-Wan, Padme and Anakin) into other timelines/parallel universes, and they get to see how a small change can alter the world they knew. This is a trope that always appeals to me, and in this case it combines with great world-building, characters I can like and some fantastic action, from light-sabre duels to space battles.

On the downside, these are the first two parts of a trilogy, and the author is fond of her cliff-hangers, but as someone who really doesn't like unfinished stories, I still found these satisfying in their own right. I should probably also point out that it may not work for you if you don't like reading about poly relationships at all, but this isn't a romance, it's one plot thread among many.

I used to read the Star Wars Extended Universe tie-in books back in the day, and I'd say this compares very favourably with most of them.