"Pure Awesome"
This is Richard Dawkins 1976 masterwork on evolutionary biology from the perspective of gene selection. The updated edition is as poignant today as when it was penned. Updates include fascinating studies supporting many of the hypotheses forwarded in the original text.
Dawkins is an excellent writer and uses non-scientific vocabulary and analogies to explain complex biological models in an easy to understand and informative way.
Other areas touched on include game theory models (the prisoners dilemma) as a basis for understanding an ESS (Evolutionarily Stable Strategy), memes (a term he coined) and computer virus.