Ezinearticle is the best article directory Check this out for the lists of article directories http://www.article99.com/ezine-article-directories/
If you want to keep it exclusive for visitors purpose--you may have a look at these two article directories who caters to only unique articles e-topic Shareyourexpertise I can assure you that --articles on these two directories are widely read as my articles there have received lots of hits. But if you are looking for general article directories --then please visit http://www.articlebasement.com
I agree with jhnrang, personally I find e-topic articles directory as one of the best articles directory, I find articles there are very professional. Even they published my Literature Articles within few hours.
Below are some of very good one.. http://www.ezinearticles.com http://www.goarticles.com http://www.articledashboard.com http://www.searchwrap.com http://www.insare.com http://www.articlepros.com you can have list on - http://www.directorycritic.com/article-directory-list.html