The Sookie Stackhouse Series by Charlaine Harris
If you tore through Stephenie Meyer's Twilight series and enjoyed it and are looking for the next step but in a more grown-up direction, or if you are in love with the HBO series True Blood and get tired of waiting for a handful of episodes every couple of years, then tear through Charlaine Harris' Sookie Stackhouse series. It's not the same as the TV show, it's more mature than Twilight. Plus - there are 9 books and counting to keep you occupied.
Tearing through a series like this is sort of like sitting down with a complete season of your favorite TV show and going through it all in just a couple of days.