Windows
The following are a few tools that might enhance the usability of Windows, specifically Windows XP. Of note, the XP Power Toys will only work on Windows XP and the Windows Server 2003 Resource Kit will work in XP and Server 2003. I have not tested the Resource Kit on any other versions of Windows.
Clear Type Tuner 1.0
Clear Type Tuner is a Windows XP (and Server 2003) powertoy that smooths fonts and tries to make them display a little more clearly. I believe this It is built into Windows Vista and Server 2008, so there's no need for it there.
[ Download | Website ]
Clutter Cloak 0.6
I guess I never added DropCloth to my tools list, but that's probably a good thing because it would've been taken off after the release of Clutter Cloak. DropCloth adds a black pane over all windows to help you focus on the one thing you care about, which you have to manually move to top of the window stack. Clutter Cloak, on the other hand, blocks out everything except for the object your mouse if over. Initially, I questioned how it was going to work, but it does... and it works very well. If you're ever interested in focusing in on a particular part of the screen, this is the utility for you.
[ Download | Website ]
Open Command Here 1.0
Open Command Here is a Windows XP (only) powertoy which adds an item to the context menu of directories which opens the directory location in a command prompt. This is included in Windows Vista and Server 2008 by using Shift+Right Click, Open Command Window Here.
[ Download | Website ]
PowerShell 1.0
Ok, I admit I'm not a huge script-kiddie, but I wish I was. I consider myself better than average, but still on the bottom rung. I've been using Cygwin for a while, now, but am more than happy to switch over to something that feels a little better. I've never been too "at home" in the *nix command line. Now that I have my command line/.NET love-child, I'm in heaven. If you've ever written a batch file, you should check this bad boy out. If you've never written a batch file, then you need to dig in. Of course, this one's not for the weak at heart. The learning curve may seem big at first, but I promise it's not as bad as you may think. And, in the end, it'll be well worth it. You owe it to the script kiddie in you.
As if PowerShell alone wasn't a great tool, here are a few extensions you might be interested in: PowerTab for intellisense-like tab completion; and, PowerShell Community Extensions, which has quite a few cmdlets and scripts.
[ Website ]
Sysinternals (Oct 30, 2008)
Sysinternals has a number of tools power-users will enjoy, but there are some that anyone would love. Perhaps the most popular is ZoomIt, which I'd recommend to anyone who ever wants to zoom into pictures. Process Explorer is perhaps the best Task Manager replacement and Process Monitor is great for seeing what an app is doing behind the scenes. Of course, these are just the beginning. I'd suggest downloading the entire suite and checking them each out when you get a chance.
[ Download All | Website ]
Tweak UI 2.10
Tweak UI is a must-have Windows XP powertoy. Essentially, Tweak UI allows you to make a lot of system tweaks such as where special directories (i.e. My Documents) are located on your file system and what threshold windows should be grouped on the task bar. Honestly, this doesn't even begin to get into everything you can change with this wonderful utility. Currently, there is no Windows Vista equivalent, but I'm sure it's only a matter of time *fingers crossed*
[ Download | Website ]
Windows Server 2003 Resource Kit Tools 1.0
I first found out about W2K3RKT when I ran into a special configuration change I had to make with IIS. This wouldn't have had me add it to my favorite tools list, tho. What ultimately did it was after finding out the kit includes two very nice command-line apps: cdburn and dvdburn. As their name [partially] implies, they allow you to burn disk ISO images to CDs and DVDs, respectively. After running into a number of issues with random GUI apps, I started using these simple tools and haven't looked back. I use the built-in Windows burning features for most tasks, but these for ISO burning. They work on Windows XP and Windows Server 2003, but I haven't tried them on Vista. I believe they also work on Windows 2000 client and server.
[ Download | Website ]