As someone who uses a WinXP box at work and a Mac at home, I much prefer the Mac. Even using the "same" apps (Firefox, AIM or Trillian/Adium, Office, web-based email) I still prefer the Mac experience. I don't appreciate having to run antivirus and antispyware software on my work machine. I don't appreciate how different Word documents take up space on the Taskbar, and I don't appreciate the clumsy, antiquated interface.
If I walked into a room with a shiny new top-of-the-line PC running Windows and a shiny new top-of-the-line Mac, I'd sit down at the Mac. That's what's important, not some arbitrary "desert island" crap question.
Apple doesn't need to give M$ more money by licensing WMA technology for the iPod.
It needs to license FairPlay (DRM for AAC) to other MP3 players - preferably ones that use Flash memory and not hard drives. That way, Apple will still have the market for the best HD-based digital music players but will expand the use of AAC files by a proliferation of less-expensive players that can use the iTunes Store.
Wherein John Gruber Picks Windows
Why the iPod Should Play Windows Media Audio