I submit to ezinearticle, searchwarp, and goarticles. I used to submit to over 10 different directories but found some of them take over a month or two to even get accepted, as well as they do not have a good PR rating. Now that I am a platinum member of ezinearticles, I can submit as many articles as I would like, as often as I would like and knowing that it is top rated, I prefer that site above all others.
I also blog as well. I do submit the same articles from my blog sometimes, just changing a few things to make it accepted by ezinearticles. They are a little picky when it comes to that as we all know.