I am not sure on the best submission service for search engines, I never tried paying for one to do that for me. I did hand submit my site to DMOZ and hope it gets accepted there. From what I understand, for DMOZ it really is the quality of the submission.
Could you try my automatic directory submission service? It's here: Cheap Submission to Thousands of Directories in Minutes - Only $6.95. It's an online live tool, which will submit to 1000+ directories in minutes, and you will watch the tool submit to the directories one by one, together with category submitted and submission status.
Thanks for the vote of confidence swedal. Yes, try our directory submission service. We have been offering a quality service since January of 2006. We also offer niche services for blogs, articles, travel and real estate directories.
I'm offering one but it's a bit pricey: http://forums.digitalpoint.com/showthread.php?t=948316 Then again, you get what you pay for.
I have a question, Does anybody know if someone offers an industrial niche submission at alll? (we deal with piezo manufacturing) So far And Matrixsoftwarez look really good.
Whatever service you use, ask for quality submissions and a minimum approval rate guaranteed, after 1 or 2 months and a spreadsheet where you can revise all your directory listings. (Some submission services wont to submit your site to hundreds of neglected directories which won't approve their submissions). Also, I think that a serious directory submission campaign shouldn't be based only in free submissions.