Because next weekend is the season 4 premiere of Game of Thrones, I'd thought I'd get you all excited by recommending some of the merchandise that's come out. This is for mostly the HBO series (because there are simply more items), although I will mention a few book related items listed herein.
Owning the series on blu-ray / hi res digital - to re-watch, and get others into it.
The books. They are out in various formats, but I recommend the paperbacks by Harper Voyager. Harper always does a really good printing job, and the books by them are a pretty decent size (not too large, not small). There are still more to come! http://www.bookdepository.com/Song-Ice-Fire-George-R-R-Martin/9780007477159
Steins. merchandise that's appropriate. Choose your house, and take a drink [responsibly of course].
Beer by Onmegang - that's right: beer influenced by the series. The stout was pretty well recieved, and the new 'fire and Blood' seems promising also.
Coasters. to put your stein of beer on. There are two 'sets' (with a stone version of set 1 available).
Bookends. There are a few but I recommend the direwolf set, pictured at post's beginning (though the ones above aren't too shabby). Great for displaying the blu-rays, or the books.
t-shirts. Choose your house, and show your support!
Lands of Ice and Fire - for watchers, and readers, follow the journeys of the characters and get a much better look at the realm. Features a lot of fold-out maps.
Swords by Valyrian steel.You know, for decorative purposes. Also, should an Other invade your dwelling. http://www.valyriansteel.com/shop/
Games - card and board by Fantasy Flight. play the Game of Thrones!
Art prints by Stephen Youll. He did the covers of the books back in the early days. The one for Book One remains my favorite so far. http://www.stephenyoull.com/stephenyoull.com/PRINTS.html
Posters. There's been a few, from the 'official posters' (book cover, blu-ray cover...) to posters of the House sigils. Decorate ye walls.
Merchandise can be purchased through the HBO Shop : http://store.hbo.com/game-of-thrones-viewall/index.php?pagemax=all&v=hbo_shows_game-of-thrones , as well as various outlets, including Chapters : http://www.chapters.indigo.ca/home/search/?keywords=game%20of%20thrones