I stumbled upon Gary Gianni's booth at Comic-Con International this year, and I was amazed by all the fantastic paintings. He had ALL of the original paintings from this calendar on display, and I was fascinated. He told me that George R. R. Martin had specifically asked him not to watch the show so that his paintings wouldn't be influenced by the show's portrayal of events. And he really nailed it. I love the TV show, but this calendar gets things a little closer to the way they looked in my mind before I saw the show. Gianni is just brilliant, and merging his painting style with something that is so fantastical AND in pop culture is just genius.
January: Jon Snow from A Dance with Dragons
February: Reek (Theon) in the snow from A Dance with Dragons
March: Cersei from A Feast for Crows
April: Ned Stark and Arya (with Needle) from A Game of Thrones
May: The Titan of Braavos from A Feast for Crows (There is also a centerfold of the Titan!)
June: Drogon going wild from A Dance with Dragons
July: Tyrion with the crossbow (yeah, THAT crossbow) from A Storm of Swords
August: Daenerys with her baby dragons from A Clash of Kings
September: A cool battle scene from A Feast for Crows
October: Melisandre birthing a shadow creature from A Clash of Kings
November: Pycelle, Varys, and Littlefinger in front of a map of Westeros from A Game of Thrones
December: The wights attacking from A Storm of Swords
The ones that I really like are Ned with Arya and the Titan. The Ned/Arya scene is a really tender moment, and one of the last happy memories you have of Ned. The Titan is just something I'd always wanted to see since I first read about it. But the best painting is clearly Tyrion, and Tyrion is true to the book in this painting. He's short, ugly, at this point completely disfigured from the war. Peter Dinklage is a fantastic actor but Tyrion isn't supposed to be handsome, he's supposed to be grotesque. And this is Tyrion's most memorable moment, with the crossbow (no spoilers!).
If you like fantasy artwork and A Song of Ice and Fire, then you'll love this calendar, although any art lover could probably appreciate most of the images, it's just fantastic.