Armada - Ernest Cline

Synopsis
Zachary Ulysses Lightman is a kid who plays 2 video games called Terra Firma and Armada a lot, and Armada so much that he is ranked worldwide. However, when a ship from the Armada flies over his house, Zack is shocked when the owner of the videogame shop he works at reveals himself to be a Lieutenant at the Earth Defense Alliance, an organization designed to protect Earth from extraterrestrial threats, and that the video games were "combat simulators" merely designed to train people for the real threats. After that, Zack is offered a spot at the EDA, which he takes up, and proves to be a smart and skilled drone pilot.
Quotations
"'We'd already won,' she said. 'We'd just destroyed all but one of their drones - but then somehow the last Glaive Fighter got inside the drone before it self-destructed,' she said. 'Somebody screwed up.'" (159)
This happened right after the EDA was fending off some enemy fighter drones, but one enters the base and self-destructs in a room full of machinery; because the drone Zack was piloting followed the enemy drone, despite orders not to from superiors, the system could not defend itself from the threat and as such, the room was destroyed. This shows Zack's stubbornness and tendency to take matters into his own hands, because Zack refused to stop following the drone - he wanted to stop it for himself and become a hero. This quality is important in the grand scheme of the book because Zack eventually has to save the world when the EDA's defenses fail by flying a ship and destroying an important structure of the enemy's. This scene is also important because it makes Zack meets Admiral Vance, an important character.

"If I died protecting the two of you and our home, then I figured it would be worth it." (235)
This is a perfect example of an important theme in this book: Sacrifice. Zack's thought-to-be-dead dad, Xavier, sent something to Zack about 15 years ago (he never received it until now), which talked about important details about his life, including this bit. This shows Xavier's willingness to sacrifice for his son, because he leaves for the EDA to save the world, and by extension, his family. In addition, he says that he would die for his family, which further shows his commitment to sacrifice. Sacrifice is an important theme because later in the book, Zack and Xavier have to take matters into their own hands, and potentially die doing it.

""Your species' primitive warlike nature made a certain amount of conflict inevitable, as it often does." (341) This was said by the Envoy, a computer run by the Sodality, the civilization on Europa (one of Jupiter's moons) behind this whole mess. It turns out that they didn't want to fight - humans initiated contact. This is the important confirmation of an important theory: that the humans started the war and that the species was peaceful (unless they were aggravated by something). This passage is also important because this reveals an important theme: Humans fight - there is lots of argument throughout the whole book between different people, and usually nothing good comes out of it. This passage (not this specific quote but the entire paragraph) marks the end of the conflict - Earth passed the Test - that they wouldn't be harmful to the Sodality.