Do you use Parallels (or other VM software)?
Do you prefer “hiding” Windows in a window, or do you hide Windows by integrating with OS X and use Coherence Mode?
In this mode the virtual machine’s desktop is invisible so that you can see the virtual machine’s application windows in Mac OS X and work with them side by side with your Mac OS X applications.
Personally I do not like Coherence Mode and will either use Windows in a Window or in Full Screen Mode.
How do you use Windows on a Mac?