I read all three of the series a few months ago and thought they were great reads. As people have said, not particularly well written, although having said that they're easy to read which probably contributes a bit to why non-readers stick at them too.
I've read comments popping up everywhere saying how it degrades women, cheapens them and is just titillating porn. I have to say I disagree. Nobody did anything sexual in this book they didn't want to. By the end of the series I felt we had gotten an insight into the mind of a troubled man who used S&M as a coping mechanism throughout his adult life to deal with a traumatic experience. He in no way demeaned or degraded women, he adored women. In fact the women were the ones in charge, he had to have their permission in every aspect of their 'contracts' and were very well treated. By the end of the series, we see how Christian himself discovers why he is the way he is and how he grows and changes with his love for Ana.
The principle character of Anastasia does start out rather meek amd mild, easily led and a bit too blushy. But as with Christian, she grows into a stronger person and we discover that she does have views of what feels right for her, she is in fact strong enough to say no and doesn't succumb to his every whim. While still remaining open and loving, she knows how to set the boundaries while possessing the desire to try new things.
The most ridiculous term I've heard about the series is 'Mummy Porn'. I find this tag rather degrading, it suggest that as a mother I am in some way dirty for reading it, and totally shameless for enjoying it. I'm shocked at some of the comments about the book from those who have not read it, or those who read it and were too busy being offended by the sex scenes, they failed to grasp the underlying story and power switch between the two main characters. I find it tedious when I read negative opinions where the person has not even read the book, but main stream media has seemingly removed their desire to form their own opinion. Ironically, as a prolific reader, so many negative comments in the mainstream about a book would spark my interest and make me curious to see what all the fuss was about ...go figure!
I understand it's not for everyone, it is pretty graphic. But then so are some books about serial killers with their graphic descriptions of mutilations, or horror books with their graphic and gory horror scenes. As for the hype, it reminds me of the Twilight series in that respect; both not particularly well written but having armies of both fans and haters.
My opinion? I thoroughly enjoyed both series'