What is the best way to manage windows?

There are a few possibilities out there for window management.

• In Mac OS, the bottom right corner of every window is draggable and will resize a window. There is no window border. Window controls for minimizing, closing and enlarging are in the top-left corner. The menu bar is at the top of the screen.
  
  
  
  • Enlarging on MacOS will resize the window to an "appropriate" size, which may or may not be full screen. (It seems that it will be no-menubar no-dock full screen in the future)
  
  
  • Windows look very clean since there is no visual window border.
  
  
  • The bottom-right corner can be pretty far away and relatively small, which can make window resizing awkward.
  
  
  • If a program somehow decides to become higher than the screen, it is very difficult to resize it to a usable size. (use keyboard to enlarge, drag corner)
  
  
  
  
  

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• In (modern) Windows, windows can be resized by dragging any window border. Hence, window borders have to be quite big. Window controls are in the top right. The menu bar is at the top of the window.
  
  
  
  • Enlarging a window will always make it full screen.
  
  
  • Window buttons and window edges are very big and make for a somewhat "heavy" feel. However, they are easy to grab and obvious to use.
  
  
  • There are several "Aero Snap" features that resize windows to a few practical sizes when dragged to a screen border. (maximize at top, left/right screen half at left/right, full height at bottom)
  
  
  
  
  

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• In Ubuntu (10.10 standard theme), there is a 1 px non-visible window edge at which windows can be resized. Window buttons are in the top left. The menu bar is at the top of the window. (It will supposedly move to the top of the screen at some point)
  
  
  
  • The tiny window borders make for a clean look, but grabbing one of those edges is excruciatingly hard.
  
  
  • Windows can be resized by Alt-Middle-drag
  
  
  • Having the window buttons and the menu bar right next to each other seems damgerous even though it did not yet lead to problems for me.
  
  
  
  
  

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• Cellphone operating systems run every application full screen. There are neither menu bars nor window buttons.
  
  
  
  • The lack of choice makes for very simple UI principles and intuitive usage.
  
  
  • There is no way to display more than one application/window at a time.
  
  
  
  
  

What do you think is the best solution usability-wise? Is it implemented in one of these examples? Is there another OS out there that implements the perfect system? Do you have an idea for the perfect system?