I just finished reading River Marked and I found that I missed being in Mercy Thompson's universe so I decided to go back to the beginning. This book is what really got me started on my Urban Fantasy / Paranormal Romance kick I'm on at the moment. It's so nice to find a heroine that is smart, tough, and has a heart. Not that there aren't other heroines out there with the same characteristics, but for me Mercy was the first I read. After this series I actively look for heroines who aren't helpless yet aren't invinsible. It makes me feel more of a connection (if you can say that) to a character in a fantasy book where it's really difficult to understand vampires, werewolves, etc. when they don't really exist in our world. 
 I like the details of pack life that Patricia Briggs sets us up with. She clearly did a lot of research on real wolf packs. It was something, at the time when I first read the series, that I had not encountered yet. 
 I liked the relationship development. It's definitely something that will take place over the series but I almost think it's more worth it to see the development rather than have a relationship start right away. When the relationship finally is decided it seems like both characters really worked for it. Initially when I read the book I had thoughts on who I thought Mercy should be with, but by the middle I changed my mind and then changed it back by the end! 
 Really this series is one of my favorites and I will enjoyed reading it again and again.