General File Sharing:

ZeroPaid [ File-sharing portal ]

Slyck [ File-sharing portal ]

UniteTheCows [ File-sharing portal ]

museekster [ Dutch file-sharing site ]

Software:

Ad-aware [ Spyware removal tool ]

Spybot Search&Destroy [ Spyware removal tool ]

The Proxomitron [ Great tool to block ads, pop-ups, cookies and much more ]

DAEMON Tools [ Tool for creating virtual CD-ROM and DVD-ROM drives. Very useful for opening/playing CD/DVD images. ]

musiCutter [ Excellent cutter/joiner for MP3 files ]

Other:

PeerGuardian Database [ Database with 'bad' IP ranges ]

Free Public Proxy Servers

Cracks, keygens & serials:

Astalavista [ Excellent crack search engine ]
GameCopyWorld [ No-cd cracks/patches for games ]
CDRSoft [ CDR & DVDR software ]