I really, really wanted to like Delirium. The concept was fascinating. "Love...It kills you both when you have it and when you don't." The distopian aspect-- I love true distopian. 
 I didn't like Delirium because it rejected everything that was good about love: stability, security, faith in one another, etc. Instead, it supported all the myths about love that lead to future disillusionment when "passion" fades, because mere passion is presented as love. I'm not saying that passion is bad, and I think that it's essential in a relationship, but it's not all that there is to a relationship. I could see no actual connection between the characters except the whole "forbidden love" thing. 
 Not only this idealism that just didn't mold for me, but the story was predictable and suspiciously similar to other stories: 
 (view spoiler)[-the fake scar of procedure = the fake scare in the host. Which I totally saw coming. Which was totally stupid. Especially when he comforted her with "I can't hurt you," which was a lie: he could have, and he did. 
 -the best friend who introduced her to the "underground" = Shay from the Uglies series. 
 ...My favorite part was that he died at the end. (hide spoiler)] 
 (I could swear Lauren Oliver is an ex-Mormon.)