A blog directory that sorts on incoming hits usually sends more traffic compared to blog directories that just sort on date (new ones first). But (there is the but) you need to send traffic to the blog directory to get on the first page or at the top of the list. If you don't send any traffic your blog will likely be positioned under the blogs that do send hits.
http://www.goldadultblogs.com/ is a example, it sorts blogs on hits. It also has a toplist in which your blog can appear when it can send much hits. It also has a search function that will give your blog hits from people that search, this one benefits from a extensive quality blog description.