Tuesday Ten - all time favourite book series

I know I've been ignoring the blog for such a long time... I'm going to be better at this blogging thing from now on, I promise *crosses heart and twirls anticlockwise three times*
In an attempt to keep some kind of schedule and not fall back into old habits, I'll have themes for each day of the week. Today, for example, is Tuesday Ten.
I have to kick this new theme off with a book related subject, so here it goes:

All time favourite book series

1. In the Company of Shadows - Santino Hassel and Ais

2. Cut and Run - Abigail Roux and Madeleine Urban

3. Adrien English - Josh Lanyon

4. The Wolves of Mercy Falls - Maggie Stiefvater

5. The Infernal Devices - Cassandra Claire

6. Black Dagger Brotherhood - J.R.Ward

7. Vivaldi in the Dark - Matthew J. Metzger

8. Captive Prince - S.U.Pacat

9. Promises - Amy Lane

10. Conquest - S.J.Frost

What are your favourite book series?