If you're okay with youth fiction from mid-last century, C.S. Lewis' Chronicles of Narnia is a very famous arc of many books and a few movie adaptations. "The Lion, The Witch and the Wardrobe", first written but not chronological, was a delightful read when I was a kid, but the later ones in the series were super overbearing in their biblical parallels and I didn't like them.

Probably the most amazing trilogy I've read in my life was by a fellow Canadian - Guy Gavriel Kay's "The Fionavar Tapestry". It starts with The Summer Tree. It's big and grand and utterly amazing, and I can't recommend it enough.