My Desktop and Dev Environment
I have two desktop machines currently, my primary machine is a Dell Precision 470 running Windows. My backup machine is an AOpen XCcube that I built myself for 800 dollars. The whole point of that project was to build as quiet a machine as possible. It runs Windows and Ubuntu and has been a great and reliable machine.
For e-mail client I currently use Outlook but only because I got a new BlackBerry. Previously I used Eudora which I found to be functionally the best. I use Second Copy for backups, Office for Word etc and FTPEditor for my web sites for the sites that I update directly.