The Host

The Host, written by Stephenie Meyer, is a science fiction-romance novel. The narrator is an alien named Wanderer. These aliens call themselves "souls" and cannot survive for more than a few minutes without a host body. Once they have been inserted into the brain of their host, they stifle the pre-existing conciousness and claim the memories as their own; they use these memories to locate humans who have yet to have a soul inserted into them. They have colonized much of Earth, save for small bands of "wild" humans that are now in hiding, and Wanderer has been inserted into a girl named Melanie Stryder who refuses to relinquish her mind and fade away. Melanie bombardes Wanderer with memories of Jared Howe (while keeping some memories blocked from her), the man she loves who is still in hiding. This causes Wanderer to fall in love with him as well. She cannot use the memories she has limited control of to help the other souls find him and Melanie's brother Jamie. Circumstances arise that force Wanderer and Melanie to become allies, and together they try to find a shelter Melanie's uncle once told her he had.
This is a very good book. The souls have a tendency towards altruism in many ways: they won't raise their hand (well, their host's hand) to harm another (which is one reason the "Seekers" who search for and capture the humans are looked down upon for the violence their job intales) or even let another being be harmed by inaction, even to save their own life. They won't try to take over a planet unless they feel the current inhabitants are doing a poor job of taking care of themselves and the planet. This selfless attitude makes Wanderer's narrative a bit on the annoyingly self-effacing and self-sacrificing side sometimes. But it's very well-written and the characters seem to be developed very well.
This novel brings up some interesting questions: is there anything else out there; if there is, how would they perceive us and the way we treat our world? But it doesn't just bring up classic sci-fi questions, it also conjures questions about love: when you someone, what is it you love? Would you love them in a different body, would they love you if you were in a different body? Can you love someone, even if their not technically your species?
The writing in this book is much better than Twilight; of course the narrator is an alien whose lived on eight planets and live what would be human equivalent of thousands of years, so she's going to have a more mature narrative. I would recommend this book to almost anyone.