"Erasing Hell" (Francis Chan) - Francis Chan is no Frank Turk.
When you're wrong, Frank Turk will slap you and say "What are you doing?" It's probably for the best that there is only one Frank :)
Chan has a much more irenic approach. He is pleading, and cajoling. I am probably not in the audience he is targeting, but I know there are a lot of people who are there.
This book is short, but very well researched and argued. If you are at all in doubt on the doctrine of Hell, and not able to take a helpful slap, this might be the book you need.
For those who are familiar with the doctrine of Hell, most of the arguments Chan presents will be familiar as well. I did learn that the notion that Gehenna is a burning trash dump is actually a medieval invention.