Badass: The Birth of a Legend: Spine-Crushing Tales of the Most Merciless Gods, Monsters, Heroes, Villains, and Mythical Creatures Ever Envisioned - Ben Thompson
Funny, irreverent and spot on. With a book that mentions everyone from Zeus and Samson to Captain Kirk and Darth Vader, you can't really go wrong. There were really only two or three peeps I'd never heard of (and it's always funnier if you have) but still pop-culturally insightful as well as some pretty darn good research on the myths and legends.

Recommended for those that like a little bit of history/pop culture with a side of irreverence.