What is the most successful movie series of all time?

I'm curious, could you enlighten me on what the most successful movie series of all time is? It's a topic that has intrigued movie buffs and casual viewers alike, and I'm eager to hear your thoughts. Are we talking about a series that has dominated the box office for decades, or perhaps one that has captivated audiences with its intricate storytelling and beloved characters? I'm looking forward to hearing your answer.