Trilogy and Series Power

  For today's A to Z Challenge topic, I'm going to be writing about book trilogies and series'. 

In recent years, it seems that more and more authors are writing a book series or trilogies. And subsequently being made into movies and a TV show for one. 

For example, the following trilogies have been popular:

                  1. Divergent Series by Veronica Roth

                               Book Order: Divergent
                                                    Insurgent
                                                    Allegiant

                  2. The Hunger Games Series by Suzanne Collins

                               Book Order: The Hunger Games
                                                    Catching Fire
                                                    Mockingjay

                  3. Millennium Trilogy by Stieg Larsson
                              Book Order: The Girl with the Dragon Tattoo
                                                   The Girl Who Played with Fire
                                                   The Girl Who Kicked the Hornet's Nest

                 4. Fifty Shades of Grey by E. L. James
                              Book Order: Fifty Shades of Grey
                                                   Fifty Shades Darker
                                                   Fifty Shades Freed

As for series':
                1. Harry Potter by J. K. Rowling
                             Book Order: Harry Potter and the Sorcerer's Stone
                                                  Harry Potter and the Chamber of Secrets
                                                  Harry Potter and the Prisoner of Azkaban
                                                  Harry Potter and the Goblet of Fire
                                                  Harry Potter and the Order of the Phoenix
                                                  Harry Potter and the Half-Blood Prince
                                                  Harry Potter and the Deathly Hallows

              2. A Song of Ice and Fire by George R. R. Martin
                           Book Order: A Game of Thrones
                                                A Clash of Kings
                                                A Storm of Swords
                                                A Feast for Crows
                                                A Dance with Dragons
                                                The Winds of Winter (forthcoming novel)

             3. Twilight by Stephenie Meyer
                          Book Order: Twilight
                                               New Moon
                                               Eclipse
                                               Breaking Dawn

Out of what I have listed, I have read the complete Harry Potter series, the first two books in The Hunger Games Trilogy and the first one in Divergent and have enjoyed all of them. And yes, I plan on reading Mockingjay, Insurgent and Allegiant. I have also read The Girl with the Dragon Tattoo, but didn't really get into it that much.

I don't mind reading trilogies and book series', but I also like reading stand-alone books as well.

That leads me to end this with a question:
Do you prefer to read trilogies/series' or stand-alone titles?

Happy Reading and Keep on Writing!

♥Meg♥