Another vote for the Diana Gabaldon Outlander series.
I also love:
Patricia Cornwell Scarpetta series
Iris Johanson- Eve Duncan series
Sophie Kinsella - Shopaholic series
Meg Cabot - any, but love the Heather Wells mystery series
The Time Traveler's Wife by Audrey Niffenegger
Jimmy Carters books are also very fun.
My daughter tells me The Hunger Games series are great but I haven't started reading it yet.