... search engines and those there are do everything they can to discourage and downgrade submissions which seem to them are automated.
But I have used AddWeb and think it is a good one to try.
I am an affiliate and supporter of Selfpromotion.com
This is my second year which means I really am im[ressed with it.
Another site with tools, templates, forums and pages of useful information and advice is http://www.jimtools.com