The bestmeaning most likely to drive trafficinbound links come from:
Sites that publish content that is complementary and related to the content on your site.
Hub sites that are a central repository, discussion area, and community site for a particular interest group. For example, a mention on SlashDot (http://www.slashdot.org) can drive huge amounts of traffic to sites related to technologyso much so that the phenomenon of a sudden up-tick in traffic due to inbound links has become known as the "Slashdot Effect".