I would rec Paper Towns too! I recently reread it and fell in love with the characters all over again, plus on the second go, I could fully see how he pulls apart the manic pixie dream girl myth. I liked his other books a lot, but that one has really stuck.

And do report back on Fault in our Stars! The main reason why I'm hesitant to read it is because I know it'll probably make me sob like a baby.