R-Drive http://www.drive-image.com/
Use it to make back up images of my hard drives. Been using it for a few years and it has come through for me multiple times.
Vopt http://www.vopt.com/
Its a disk defragger that works really well.
Jungle Disk http://www.jungledisk.com/
This is possibly the greatest thing ever. It backs up your shit to amazon's s3 storage. Very cheap and reliable online backup. You can even encrypt your files before uploading them.
Wallpaper Changer http://www.wallpaperchanger.de/
It's a little old but gets the job done.
Startup Inspector http://www.windowsstartup.com/
This gives you a list of all the applications that start up with windows and allows you to turn off what you don't use. And it's free!
Blink http://free-antivirus.eeye.com/
Great all in one firewall, anti virus/spyware. It does use a decent amount of memory. I would not recommend it unless you have more than a gig of ram.
CDBurnerXP http://cdburnerxp.se/
A free cd/dvd burning program. It always works for me.
I also use Photoshop, Dreamweaver, Office, and Visual Studio.