Into the Wild - Jon Krakauer
This book broke my heart. I will forever be haunted by the story of Chris McCandless. You'll admire his tenacity and wanderlust, his willingness to give up a privileged lifestyle, and you'll want to slap him upside the head for his naivete at thinking he could take on the brutal Denali wilderness ALONE. And the ending will make you say "OMG! You must be kidding! How could he NOT know?!"