The first time I read Nimona I was a little ambivalent about it. I kind of wish I had read it while it was being published on the web (I followed Noelle Stevenson's tumblr but never read Nimona until it was published). I think the serialization would have helped me enjoy it more the first time.
I enjoyed it more when I reread it earlier this year. I was feeling bad but found the story uplifting. Sometimes monster girls' stories are just what you need.