WinKey + Tab key= To see all open application tiled. Press and leave the Tab key (Toggle press the tab key) to make the application move to the right. Right most application will become active window when you leave the key.
WinKey + Up Arrow and Down Arrow= Maximize and Minimize the application window.
WinKey + T= Iterate through items in taskbar.
WinKey + L= Lock Windows
Ctrl + Shift + Esc= Task Bar
WinKey Left Keyfor an app, then winKey +RightKey for another app = Snap and compare. Or you may be typing something on notepad while seeing on Browser, etc. Very useful!
Winkey + "+" or "-"= WinKey + Plus key or minus key for magnifying or minifying the area where mouse pointer is positioned.
WinKey + Esc= remove the magnifier if enabled by previous command.
WinKey + 1/2/3/..= To activate the application in taskbar. (and it starts from 1 and not zero. )
WinKey + P= Display and projector toggle.
WinKey + D= Toggle to desktop. You all know!
Alt + Esc= Goes through the sequence, you opened your window.
WinKey + Space bar= It is for aero peak. Not sure why to use this. May be I have not given the right environment to see its effect. I see one effect of this is when I press WinKey + spacebar then I see desktop visible temporarily.
Remember, WinKey is also called Super key, Meta key or window logo key.