I just finished reading The Host by Stephenie Meyer and I loved it.
Its totally different to the Twilight series but it also has a fantastic storyline.
Basically, Earth has been taken over by aliens by invading on human bodies and erasing personalities but keeping the body intact and continuing in a normal life. But the alien (Wanderer) takes over the body of Melanie Stryder who is resisting and does not want to give up her body. Wanderer and Melanie end up working together and with Melanies memories they end up traking down her past life and love.
I really enjoyed it and cant wait for the sequal!