X-Search has been in operation since 1996. They accept submissions to their search engine and host extensive model and celeb directories.

http://www.x-search.com/      (popularity:  ; clicks: 81; comments: 0)      

PR: 2

This is the adult section of the DMOZ Open Directory Project, which is the largest human-edited directory on the internet.

http://dmoz.org/Adult/      (popularity:  ; clicks: 66; comments: 0)      

PR: 5

Booble is an unbiased adult porn search engine and porn directory which provides users with a free porn search, porn categories search, cam site search, adult personals search and erotica search; and we also offer free porn galleries and sex toy shopping.

http://www.booble.com/      (popularity:  ; clicks: 72; comments: 0)      

PR: 5