Book Talk: Favorite Book Series

Okay, I'm sure we've all read some pretty awesome book series. There are a plethora of series out there... so, what is your all time favorite series? That maybe a hard question so how about what are your favorite series?

Here are some of mine (keep in mind I've only read a few series) in no particular order:

Gone by Michael Grant
Hunger Games by Suzanne Collins
Uglies by Scott Westerfeld
Vampire Academy by Richelle Mead

Here are some series I want to start (yes I am very late...):

Harry Potter by J.K. Rowling
Divergent by Veronica Roth
Mortal Instruments by Cassandra Clare
Chaos Walking by Patrick Ness
The Maze Runner by James Dashner
Leviathan by Scott Westerfeld
Eon & Eona by Alison Goodman
Percy Jackson & the Olympians by Rick Riordan
Ender's Game by Orson Scott Card
The Girl with the Dragon Tattoo by Stieg Larsson

Here's a site that lists book series in order

I really do love series. There's just something about being left at a cliffhanger and having to wait for the next book to see what happens. The first book is amazing, we are introduced to a new world, new characters, and the author's writing style. We get to see the characters really develop and be become attached to them. At the end of a series is sad since it's over, but we get to see where the author was leading the story and the finale of it. Afterward, we think about the story and do some more reading about it online (or at least I do) :).

Please, feel free to discuss anything in the comments such as:
What are your favorite series? What series did you not enjoy? Do you want a movie to be made out of a series?