I'm a huge fan of both the (long, long) books and the HBO series. I'm a book lover first and foremost, so I will almost always answer the book, to the question which is better?
However, one thing that the show has all over the books is the beautiful sets and clothing. This past Sunday was King Joffrey's wedding, (no spoilers here!), and just look at a few of the costumes for this event. (If you click this picture, it will take you to the photo exhibit pictures, which are larger and more detailed and dare I say, FANTASTIC!)
These pictures aren't from the wedding episode, but mostly their everyday wear on the show, as ladies of the realm.
Look at the detail on Cersei's dress. It truly is fit for a queen. A better queen than she, but I digress.
And Sansa's embroidered dress:
And the back of her cloak:
I'm a tomboy and always have been, but one day...one day I would love to wear a dress like this.