To those who criticize this for not being exactly like the books I can only say that you don't understand the word adaptation. Had the BBC filmed the books faithfully it would have resulted in about 40 hours of TV rather than 4 hours. Nobody other than the truly terminal geek expects a TV or film adaptation to be a simple shooting of a book, that's why they call them adaptations. I can only think of one TV show where that happened and that was the admitedly brilliant Brideshead Revisited. That was a very slim novel but still ran to over ten hours of TV. And there was nothing in that novel that would not be easy to shoot for TV.
Of the commenter who asks if reviewers have actually read the books I can only ask: Who cares? You remind me of those music snobs who look down on people who hadn't heard of a band until they made it to the charts. Is it now a legal requirement that to watch an adaptation you must have first read and enjoyed the books? Of course not. I'm sure you've seen TV and film that you were not even aware was an adaptation. That's not a problem and would not impact your enjoyment either way.
So for the record: Yes I read (and re-read) and enjoyed the novels. And I enjoyed the TV adaptation too. I didn't expect it to be faithful to the books any more than I expected, say, Stardust to be faithful to it's novel. It's an excelent and enjoyable adaptation. And it's the latter that counts.
Those who don't enjoy it because it isn't faithful to the books should take a look in the mirror and realise that they are looking at Fat Comic Book Guy from the Simpsons.