Until recently, I worked on a Windows box (even if it was often little more than a display device for my Xterms running on a Linux box). Now, though, I’m using Mac OS X, which seems better all round.
Just one problem, though: I’ve become addicted to the Python Windows documentation browser. I know my way around the documentation hierarchy and can quickly open and close nodes to get where I need to. The search is good too. Unfortunately the Windows help only runs on Windows, and clicking through the online documentation at http://docs.python.org/ was getting frustrating.