Fyodor recently announced an update to what was previously called “Top 75 Network Security Tools”. The new list, compiled from votes cast on the nmap-hackers mailing list, has grown to 100 tools, including recent newcomer MetaSploit, which did not exist at the time the previous list was produced. You can see the new Top 100 Network Security Tools here. Fyodor does not permit votes for his legendary tool Nmap, since the poll is conducted on an Nmap-focused mailing list, and Nmap would certainly take the top spot (and rightfully so).
In a somewhat related note, another legendary security tool, Ethereal, has been acquired by a private concern, who, due to a trademark dispute had to relinquish the Ethereal name. The tool is now known as WireShark, and appears in the #2 spot, right behind Nessus, on Fyodor's list.