I’m going to go ahead and share this list of 5 science fiction series that I have enjoyed reading. I have been working on this list for a bit. Depending on how you count the books some of the series have more or maybe less, but I have provided links over to Good Reads so you can see the more exhaustive listing of all the books in the series. You may have a different listing of your favorite 5 science fiction series. That is totally ok by me. Feel free to share other high quality series that I should check out. You have a good indication based on the below list the types of things I enjoy reading. 

• Dune (6 original books) happens to be my all time favorite series. This is probably the set of books I have read the most. The first 6 original books are my favorite set of the Dune universe, but I have read every other book in the series up to now. 
• Expanse (9 books) I’m sure you have heard about the books by James S. A. Corey. They quickly became a new addition to my list. It is rare that during the course of reading a book series I cannot wait to find out what happens next and push on past my bedtime, but a few moments in this series had my complete attention. 
• Ender saga (12 books) I’m a fan of both the regular saga and the shadow series of books about Ender and Bean. Considerations about the author aside, I have enjoyed the series of books and have read them more than one time as a complete work. 
• Foundation (7 books) Yes, you can watch this series on Apple TV these days and I don’t think it resembles the books. It’s an adaptation for sure. I think the regular foundation series holds up pretty well all things considered.  
• Kovacs (3 books) The most adult series on my list is also a more recent set of books by Richard K. Morgan about the life and times of Takeshi Kovacs. Just to be clear on this one I would read another round of books about Takeshi. I think some room exists for more adventures somewhere in the universe of Takeshi Kovacs. 

Postscript: My affinity for one of these series of books is not an endorsement of any author as a human being or anything like that. Why that would be an expectation of things like a book list is beyond my understanding. Assuming the author is capable of producing world class and renowned prose that is readable, epic, and otherwise delightful I’m willing to be glad that they did. We can always debate or consider other parts of a person’s life and beliefs along the way. To me a book is what is contained on the pages from start to finish. I’m willing to judge that book and decide if I want to read it and enjoy the content contained within the pages.