With the addition of three new links to the District of Columbia's webpage, I have concluded adding all known links from the EveNDon website for United States' directories.
However, there are many other directories on that website from other countries, which I will eventually link to. Also, I just discovered that Don has stored some digital copies of U.S. directories on the DocStoc website; again, I'll be adding links to those as well.
You may notice that as you peruse the EveNDon website that I may not have listed every resource for a location that is available on that site. That's because I tried to stick closely to directories only; there are many gazetteers listed under the directory category on the EveNDon site, but I only linked those that had some sort of directory in them, like a business directory.
EveNDon have great resources and many digital books on their website beyond city directories, which I highly recommend you use for your genealogical and historical research!