Jan Brett and Patricia Polacco are two of the most prolific and engaging author/illustrators alive today. And they both have a great love for Christmas, as evidenced by the large number of Christmas themed books in their respective ouvres.
Jan Brett, who lives in the Berkshires, is almost always photographed in a wool fair isle sweater. This should tell you something. She is serious about Christmas, serious about winter, and serious about graphics.
Her Christmas and winter themed titles all posess a wonderful graphic quality--bold lines, strong colors. She is influenced by nature (of course) and by scandinavian culture and aesthetics. Her drawings are very detailed--much more detailed than I am usually attracted to--yet never too much. And she has a wonderful imagination--where animated animals and other-worldly creatures are as natural and the sun in the sky or snow on the ground (like the polar bears and trolls in Who's That Knocking on Christmas Eve?). And her more traditional titles, like The 12 Days of Christmas are completely enchanting, too. Here are a few of her best Christmas titles:
Patricia Polacco, mentioned before on LLB, is always a winner to my mind. Her stories, often drawn from her own childhood in rural Michigan, or her Russian heritage, always have the perfect blend of grace, charm, beauty, and tradition. My favorite of her Christmas books is Uncle Vova's Tree, but also lovely is The Trees of the Dancing God's which is about a Jewish family that pitches in to help a Christian family celebrate Christmas when they all come down with scarlet fever. All these books have her rich illustrative style--a mix of pencil with watercolors, vibrant, cheerful, and cozy.