For this Top Ten, I could only come up with five answers to fit the topic. A lot of the series I love the most haven't been finished yet-or if they have, I've read every book as quickly as I could!
1. The Mortal Instruments series by Cassandra Clare
I loved this series when I first started it, all the way through the third book. I had thought it was only supposed to be a trilogy, but when the fourth book came out, I still picked it up. In finishing the fourth book, I felt like it was a series that should have stayed as a trilogy. I haven't read any of the other Shadowhunter series Clare has written either.
2. Uglies series by Scott Westerfeld
This is another series I feel should have stayed a trilogy. I thought the first three were really interesting, but when I went to pick up the fourth, I just couldn't get into it.
3. Hush Hush series by Becca Fitzpatrick
I liked the first book in this series just fine, but wasn't invested enough to check out the second book.
4. The Wolves of Mercy Falls series by Maggie Stiefvater
This seems to be a trend for me, where I like a first book of a series, but unless I get really invested, and pretty quickly read the next book, I tend to lose interest.
5. A Great and Terrible Beauty series by Libba Bray
I think this one was a casualty of my having so many books to read. I have entire to be read bookcases, so I've stopped going to the library as much (plus I moved, so I no longer live two blocks away from one of the biggest libraries in the city). I read the first two books in this series, but just never got around to finishing. By the time I remembered, I'd forgotten so much of the previous books, and had lost interest.