Linux
Its strikes fear into most Microsoft tech guys. At least it did me for a long time. As much as I wanted to understand and play with this OS, I found myself frustrated and lost when trying to get video drivers installed, a newer version of Firefox, or trying to get my sound card working. For a windows tech guy that has worked in windows for over 10 years, this was very frustrating. I must point out that this was a few years ago, looking at RedHat 6 and Mandrake 8.
Today I feel Linux is must better with hardware support. This is a great thing for people like me that wants to try something different. I have installed Ubuntu a few times and it has only had problems with one piece of hardware. My winmodem. This I can completely understand. The modem was designed to run under Windows, hence the name winmodem.
Broadband is on it's way to my house, and when I am able to get online with broadband, I will have another go at Linux. Maybe try Open SUSE this time. :-)
Another article about Linux being a great replacement for Windows XP and even Vista here. n-joy!
Desperately seeking alternative computing - TMS