I have. An entire set of bedroom furniture once. I've sold several things successfully -furniture, televisions, dvd's, and a kitchen appliance. I also met my husband through a personals ad there. But, of course, I didn't pay for him. ;)
It's a great and useful tool. People do tend to be flaky. If you're selling anything big (furniture, etc.), a lot of folks will want to 'come look' and never show or never respond after they send the first email. If it's gotta go fast, CL isn't always great - unless you're going to toss it into a bargain basement. BUT, it's wonderful if you have a little time and patience.