Here is a bunch of stuff that I approve of which you may find useful.

Malware, Spyware, Trojan, etc remover: - good pc cleaner for use about once a month, or when things just seem bad

AVG Free - Fantastic antivirus software that doesn't use much RAM, but protects your PC 24 hours a day! Also has a cool link scanner to check internet links for blacklisting before you click them (puts green checks or red Xs next to search links). Must have!!

 

Registry Cleaner - great registry cleaner that doesn't run in the background (still trying to find a newer link)

 

Cooliris - a truly awesome way to search the internet for pictures and videos! Quickly search through picasa, flicker, youtube, hulu, google images, yahoo images, your computer, preset channels, and more! Works for Firefox, IE, and Safari (Mac version).