Toolkits
Let's save on trees. With some notable exceptions, rather than list hacking utilities we've already covered, here are some sites that categorize them (in their droves).
SecTools.Org
The Top 100 on the site from hacker-on-high Gordon "Fyodor" Lyon (of NMAP fame), is pretty much hacker Heaven with items being voted for by Insecure.org's learned users:
TREACHERY UNLIMITED
TU is jam-packed with tools, has hacker news, malware advisories, and great features:
WASC Web Application Security Scanner List
The WASC lists the lowdown on vulnerability testers. Its Evaluation Criteria helps us to weigh up the choices, which really is far too helpful: