Comment 5? (Score 1) 280
Windows and Linux at work [1]; OS X at home [2]; iOS on my iPhone, iPad, and new Apple TV; and whatever iPod Nanos run [3].
If you get into versions, it's XP for all the Windows work; Redhat 4, 5, and 6 for Linux at work; currently straight Debian (I think Sid?) at for Linux at home; mostly Leopard through Lion for OS X [4]; and iOS 5.
Oh, and I have a dev edition of an Intel tablet I got for free that I've booted exactly once. I think it runs Maemo or Meego or something?
Do we count firmware? I'm pretty sure my receiver, TV, Blu-ray player, and cameras all run things sophisticated enough to be called OSs....
[1] And very occasionally Solaris (8, mostly, I think).
[2] With occasional interludes of Windows or Linux at home, mostly via VMs.
[3] Also miscellaneous earlier iPods, from original up to 3rd gen Shuffle, that get used an average of once a year.
[4] And one ancient Tiger box I boot maybe once a year.