I've been a fan of the series for quite a few years now. Definitely my favourite. The TV series was pretty damned good too, but I think they try a bit too hard in some places. Didn't have to show quite as many boobs and all that.
I'd say it's in the same scale as Tolkien (although not as deep - no entire languages and history of the world and all that), but much more nitty gritty and realistic. Almost like you could see it happen during Europe's feudal times. It does get more and more fantastic (as in, fantasy) as the books wear on - I wasn't too happy with that, but your mileage may vary.
I haven't picked up the last book which came out a month or so ago, but I fear that George R. R. Martin will be very hard pressed to finish the series. It might get the Wheel of Time symptom where the more you write, the less happens... but I hope not!
We'll see
