The sites listed below are sites that carry software I use and recommend.

Visual Studio Express
Specifically: C#. If you're into programming then you should check out Visual Studio Express. Microsoft offers several of its language IDEs for free for public use.

Spybot Search & Destroy
Help keep your computer spyware free with Spybot.

mIRC
The best Windows IRC client around. Come join in #Kyoto on Esper.net (irc.esper.net).