Picking the best book series of all time can depend on many factors such as sales totals, critical acclaim, and fan base numbers. This list takes all of these things into account, but mostly it focuses on the series of books that continuously succeed in transporting readers into worlds of vivid imagination with intriguing casts of characters and unforgettable plots.

Not surprisingly, many of the best book series fit into fantasy and related genres. Not only have they become more popular in recent years, but they have stood the test of time for audience excitement, engagement, and sheer loyalty.