Wheel of Time! I'm in my second re-listen now, book 6 or so. It's such an elaborate and well thought-out world, and of course 14 books that read as a single big story postpones the post-book depression... Well, not quite indefinitely, especially if you read other things like The Martian in between (that's my favorite book btw), but it limits it to once a year and a half rather than every month and a half.