Here are my top 25 favorite book series to read ever. I have posted the first book in the series with the link to a website with a synopsis (typically the author's official website) embedded in it with each listing out of the 20. I LOVE LOVE LOVE these books and really hope that the people who see this and then go out and read them later will enjoy them, too.
1. Percy Jackson and the Olympians: The Lightning Thief by Rick Riordan
2. The Books of Beginning Book 1: The Emerald Atlas by John Stephens
3. The Finishing School Series Book 1: Etiquette and Espionage by Gail Carriger
4. Warriors by Erin Hunter
5. Ruby Red: The Ruby Red Trilogy by Kerstin Gier
6. The Ever Afters Book 1: Of Giants and Ice by Shelby Bach
7. A Wrinkle in Time: the Time Quintet Book 1 by Madeline L'Engle
8. The Chronicles of Narnia: The Lion, the Witch, and the Wardrobe by C. S. Lewis
9. The Harry Potter Series Book 1: Harry Potter and the Sorcerer's Stone by J. K. Rowling
10. Tales of the Frog Princess Book 1: The Frog Princess by E.D. Baker
11. The Kane Chronicles Book 1: The Red Pyramid by Rick Riordan
12. Inkheart: Inkworld Trilogy Book 1 by Cornelia Funke
13. Artemis Fowl: The Artemis Fowl Series Book 1 by Eion Colfer
14. The School for Good and Evil Trilogy Book 1: The School for Good and Evil by Soman Chainani
15. The 13th Reality Book 1: The Journal of Curious Letters by James Dashner
16. City of Ember: The Ember Series Book 1 by Jeanne DuPrau
17. Kingdom Keepers Book 1: Disney After Dark by Ridley Pearson
18. The Unwanteds Series Book 1: The Unwanteds by Lisa McMann
19. The Magic Thief by Sarah Phineas
20. The Secret Series Book 1: The Name of this Book is Secret by Pseudonymous Bosch
21. The Selection Series Book 1: The Selection by Kiera Cass
22. Incarnate: The Incarnate Novels by Jodi Meadows
23. Young Wizards Book 1: So You Want to be a Wizard by Diane Duane
24. Five Kingdoms Book 1: Sky Raiders by Brandon Mull
25. Fablehaven: the Fablehaven Series by Brandon Mull