Going Postal, by Terry Pratchett

I listened to this one as an MP3 download, masterfully read by Stephen Briggs who manages numerous voices and nails the wry tone of Pratchett's writing.
The story was good, too. It follows the adventures of a con man given a second chance. It's set in Ankh-Morpork, a fictional city familiar to fans of Pratchett that features representatives from numerous fantasy races, a city watch that features a werewolf, the Unseen University for the training of wizards, and a healthy serving of general silliness.
All in all it's a fun story, humorous and light. It serves as a great entry point for those who have never before read Pratchett, but will also appeal to the author's longtime fans.