I'm pretty sure that series was what sparked off the whole "strong female character in a dystopia and/or post-apoc world" fad that YA is going through now. It's the first one I remember, anyway. Then came Hunger Games, Divergent, Eve, Pure, Ashes, Forest of Hands and Teeth, etc.
But yeah, it was a pretty good series. I don't know why they never made movies for the series, but I'm kind of glad they didn't. I imagine the Pretties would have to be pretty heavily CGI'd to be as perfect as described in the books and would therefore reside firmly in the Uncanny Valley.
My favorite part of the series are the hoverboard things. I want one.