Ready Player One is technically fiction for adults, but it will appeal to young adults too. The setting is a dystopian future, where people use an elaborate online world to escape the despair of the real world. Buried deep in the world are clues to finding a hidden egg. Finding the egg is worth billions of dollars, so Wade Watts, our protagonist, and just about everyone else is looking for it. The novel is full of 80's pop culture references, so if you were around for any of the 80's you will enjoy the nostalgia factor. This is a very entertaining read, especially if you are old enough to remember the 80's!
Legend by Marie Lu
Homeland by Cory Doctorow
Ender's Game by Orson Scott Card