Try: 

Avery Shaw Experiment by Kelly Oram: It's not known at all, but it's really good and cute. Also Greyson is just so... I don't know how to describe him. But he's awesome okay?

V is for Virgin: it's not what you think it's about and very good. I've heard a lot of good things about it, but many people are scared off by the title. I was, but my friend made me read it and I thank her very much.

The Fill-in Boyfriend: You are going to hate the main character at first, but she goes from shallow to a good person throughout the book. Character development was very good in this novel. As for the main guy... he's you can't hate him.

You said you liked John Green, so I suggested these. They're kinda like his writing.