Nobody can dispute what craigslist has become. It's simple, easy to navigate, and has lots of great features. BUT it's not yours. So why not start your own classified ads and make money from them.  Some of the software forces you to charge a fee to anyone placing an ad, others don't find what's best for you. You will have to have a domain host and a domain name for the ad site, but hey that's a small price for the potential.

Classified ad software

 

Brilliant Directories

Noah's classifieds

Joomprod

Caspio

Classifiedsads

Marketgrabber