Brian Patterson: There are generally good quality directories in each niche that are good initial targets on a new campaign. ;I'd completely avoid the stuff built to pass PageRank/SEO value, and instead look for those passionate curators who maintain a directory in the niche because they absolutely love it.
Tony McCreath: Make market specific searches and see what directories rank.
Ace Site Creator: I think he is asking the best ways to get backlinks. For me recently, I found the best strategy is to make videos, put them on Youtube and link them back to your site.
Frank Rodr�guez: ;do what ace says...plus your videos will appear in search. Another powerful source is Slideshare. Cheers