miniMIZE - miniMIZE catches windows that you minimize and puts a thumbnail of the main application window on your desktop. This is great for getting a visual representation of your taskbar and makes more sense to me. It also creates an uncluttered taskbar.
Launchy - Launchy indexes the programs in your start menu and can launch your documents, project files, folders, and bookmarks with just a few keystrokes! It is like QuickSilver for the Mac and makes finding and launching stuff on your PC a breeze and joyful. It supports plugins, skins and more. Just hit Alt+Space to get to it after you install it.
Defraggler - A cool defragmenter tool that lets you easily defrag the files you want to, without having to process the whole drive. Once you run it it shows you list of the files and the number of fragments per file. Now you can target just the major defragmentations.
hott notes - Post-it pads for your windows desktop, without all the fuss. Supports lists or notes format and you can set reminders and alarms as well.
Eraser - Its like an eraser for your PC with options to integrate into the Recycle Bin. It completely removes sensitive data from your hard drive by overwriting it several times with carefully selected patterns.
CCleaner - The C stands for Crap and it does just that. The program is split into 3 sections, Cleaner: which finds crap in your Windows, System and IE folders, Registry: finds errors in your Windows registry, and Tools: does Uninstall and Startup tasks.