Raymond Feist’s Riftwar series (starts with Magician: Apprentice and Magician: Master). It’s a great series overall though the books are a bit inconsistent in quality. The opening 4 books are superb though. And I would strongly recommend any fantasy fan read the two magician books, if nothing else.
The Rook series by Daniel O’Malley, Iron Druid by Kevin Hearne, Libriomancer by Jim C Hines and Rivers of London by Ben Aaronovich are all really good series with good world building to read while waiting for Dresden too. Iron Druid and Libriomancer are finished but they were only a few books long.
He had a bunch of personal life drama after 2013 that involved a divorce, a move, building a house with radioactive complications, a wedding, and a second divorce.
He seems to be back on schedule though.