I Am Number Four by Pittacus Lore (Audiobook) A teenage boy is one of nine aliens, the last of their kind, hidden on Earth. There is another alien race trying to destroy them. The kids wear a charm that makes it so they can only be killed in a certain order. When one dies, a ring burns into the skin of the others.
A third ring just burned into John’s ankle, and he is number four. No pressure. Try to live your life knowing there is an army of alien soldiers looking for you!
I enjoyed this book on many levels, because it is, you know, aliens. But this isn’t anything deep to make you think. In fact, they probably don’t want you to think much at all, because there is a huge plot hole that never got plugged for me (no matter how hard they tried to explain it away.)
The “hole” was this: The bad-guy aliens invaded #4’s planet and killed almost everyone. These 9 kids got away. The bad guys now have the planet, and have almost used up all the recourses. So, my question is: why send soldiers to kill the kids? Yes, they try to explain this away, but the plausibility never cemented for me. I just didn’t buy it. But while that particular hole screamed at me in almost every chapter, I was able, for the most part, to suspend disbelief and just enjoy a nice, fun ride.
Yes, I would recommend this, but don’t expect rocket science. Just enjoy an interesting and fun story.
Jennifer M Eaton 
I have read the whole series because I love John (#4) and Six. I thought the Mogs were killing them because they know the Legacies could defeat them. Of course, in later books we find out the Mogs are using people with legacies to create their own half-breeds with super-human powers. It isn’t a deep read but it’s fun.