Spybot Search & Destroy - Free adware/spyware/trojan remover
http://www.spybot.info/en/index.html

FTP Surfer - Awesome Free FTP program
http://www.whispertech.com/surfer

Mozilla FireFox - Nice free alternative to IE
http://www.mozilla.org/products/firefox

WinAmp - Better than WMP and Real Player
http://www.winamp.com

WinZip - Best and most popular ZIP archiver/extractor, unlimited free trial
http://www.winzip.com