Well I watched the first season in about 3 days. I enjoyed parts of it, especially the whole setting. I haven't read the books so I don't know how they compare, but I will definitely watch the second season.
I would also argue that this isn't quite on the level of some of the other series HBO has put out (The Wire, Six Feet Under, Etc.). Just my opinion, however this is a good show worth watching if you are a fan of fantasy.