Lets see I read a few good ones over the last year or so.... 
The Other Boleyn Girl, The constant princess and The Queen's Fool - Philipa Gregory they were all really good.  The other Boleyn girl was the best though!  (kind of a series although each stands alone) - about King Henrys court!  bunch of bad girls and boys!  hehe
The Odd Thomas Series by Dean Koontz, 
Odd Thomas, Brother Odd and Forever Odd.  Now there are 2 more in the series woohoo 

  - they are freaky in a way, koontz is a lot like stephen king except not so detailed.  
The Circle Trilogy by Nora Roberts - 
Morrigan's Cross, Dance of the Gods, Valley of Silence - a romance/vampire/mystical series - pretty good.  
Then of course the Twilight Series - Stephanie Meyer - 
Twilight, New Moon, Eclipse and Breaking Dawn  another vampire/love series - I love vampire books, these are good vampires though - vegetarians if you will who do not feed off humans and who have emotions.  Can't wait for the movie in Dec
Think I have a series theme going on here??  haha