"Where Clean Teen Fiction Abounds"

I learned about Novel Teen at the American Christian Fiction Writers conference, held this weekend in Indianapolis, and thought it might be helpful for those who want to recommend good reading to the teens in their lives. While I don't necessarily recommend every book featured on the site, it's a good starting place. Don't neglect the classics, though. They're called classics for a reason; they cross over the generational lines to address issues common to mankind through the centuries. They're never dated. Novel Teen is sponsored by Word Press.

What books--classic or contemporary--would you recommend? Why?