I tend to use a single maximized app in a GUI environment, often running emacs, though I do like to split the screen in half to allow two full-page, focused views (e.g., code editor and browser). And when helpful, I'll pull up more windows.
See also http://lifehacker.com/5689579/five-best-distraction-free-wri... for others who have felt the need for focused tools that remove the distractions of multiple window environments.