Cancer Omega
A.k.a Attrition Group.

RedBoxChiliPepper
The guy who started a phreaking movement called the Phone Losers of America (PLA).

BlueFish
Member of the Eleventh Alliance Development Team.

Defensive Thinking
Hacker Kevin Mitnick's security consulting / training firm.

Knowles, William
Founder of C4I.org and moderator of InfoSec News.

TexorcisT
Founder of Collusion Group.

Uttula, Markku
Markku Uttula's View of the Personal Computer World Now and Yesterday.

Amini, Pedram
Pedram Amini's current projects, research, and code.

Ðara, Rishabh
Hacking Tools, Exploits & Ebooks

Wandtke, Kamil
Scripts, Programs and Tutorials by Kamil Wandtkw (aka "taoo").

Hosey, Roger
Security Tools and Guides by WhiteHat Hacker / Security Consultant Roger Hosey.

Raptor
Provides information on computer security research, privacy, and hacking. The author presents his projects, exploits, papers, code, and configuration templates.

Free Lamo
Forums, donations and support to Adrian Lamo (the "homeless hacker") defense fund.

Space Rogue
Website of former member of L0pht Heavy Industries and editor of the Hacker News Network. Biography and articles.

TLC.com: Hacker's Hall of Fame
Biographies and photographs of 15 famous hackers. [Requires Flash.]

Linuxdevcenter.com: The Hacker Behind "Hacking the XBox"
Interview with hacker Andrew "Bunnie" Huang describing how he ran into trouble with the DMCA when publishing a book on hacking the Xbox.

Enquirer.com: Hacker claims he was working for FBI
Article on Jesse Tuttle, a hacker who used the handle Hackah Jak.

Wired.com: Wau Holland
A story of a German hacking pioneer and co-founder of Chaos Computer Club (CCC). Famous hacks include BTX and NASA.

Archibald, Neil
Neil Archibald's personal blog about computer security, programming and related information technology subject matter.

Ritter, Ben
Personal home page of Ben Ritter, who is also known as skape.