I have discussed on how to Get Targeted Traffic using classified ads, but this topic is incomplete without listing the best classified ads sites. There are many other classified ads website, but the below listed ones are the best as the time of writing this article.
Please, before I list them, I will like to advise you to have a different email account because you may get many junk emails from people. Below are the Best classified ads sites:

http://www.craigslist.org

http://www.backpage.com

http://www.pennysaverusa.com

http://www.usfreeads.com

http://epage.com/

http://www.classifiedads.com/

http://www.freeclassifieds.com/

http://www.classifiedsforfree.com/

http://adpost.com/

http://adlandpro.com/

http://www.olx.com/

http://www.ebayclassifieds.com/

http://www.oodle.com/

http://www.gumtree.com/

http://www.recycler.com/

http://www.sell.com/

http://businesslist.com/post-classified-ad/

http://www.thefreeadforum.com/

For me, I have had a good success using craigslist, backpage. I love these sites because of the targeted traffic I get from them.