Note: I've never seen the series, I've only read the books.
Game of Thrones is EPIC. Like, all capital letters style. It's not situation driven, where you know what the deal is within the first five minutes--actually, you don't really ever know what the deal is because it will flip the script on you without warning, just like real life. It's not something you back into and suddenly you're hooked. It's not a clearly defined hero and a clearly defined villain. It's complex, one of the most complex things I've ever read, and complex doesn't mesh with easy. It takes an investment. You have to remember things, you have to think about things, you have to put two and two together because it doesn't always do it for you. It does not pander, it does not coddle. If you're not willing to make that investment then it's probably not for you.
It will also take traditional ideas about a fantasy narrative and bash them over the head with a morning-star. It's better written than 99% of the fantasy genre and it's more intelligent than 99% of the fantasy genre. It's probably the most important thing to happen to the fantasy genre since Tolkien scribbled a narrative atop an assortment of European mythologies (or copied Wagner, whichever you prefer).
