I'm not sure DMOZ was the largest directory; Thunderstone has one which claims to add 250,000 links a week, but it's organized automatically by computers. As a demo of their technology it's impressive, but the results still aren't on par with a good human-edited directory.
There have also been a few wiki-based directories. Those are usually large, but they kinda become a free for all mess.
Perhaps DMOZ was the largest quality directory.