A short list of programs for Windows I reccomend:


Styler - Custom Explorer.exe toolbar, apply and control Visual Styles easily and some other nice features.
http://www.crystalxp.net/galerie/en.id.551.htm

RKLauncher - Easy-to-use customizable dock.
http://home.cogeco.ca/~rklauncher/

TClock 2 - Customize your systray clock and a few other things.
http://shii.org/tclock/

Samurize - System monitoring and useful desktop displays.
http://www.samurize.com/modules/news/

IconTweaker - Customize Icons easily.
http://joost.endoria.net/home

WINAMP - Great and easily-customizable media player.
http://www.winamp.com/

Firefox - If you don't have Firefox then I lol at you. I suppose Opera's ok.
http://www.mozilla.com/firefox/