Keyboard shortcut to unhide or unminimize a window in OS X
A very quick keyboard method to un-minimize a specific window or un-minimize all of an app's minimized windows is this:

Command ⌘+Tab ⇥ to the app with minimized windows, but don't release the Command ⌘ key.

While still holding Command ⌘ down, tap Down ↓ or 1 (easy 1-handed access) to enter App Exposé. Once in App Exposé, all keys can be released.

To un-minimize all windows, select any window with arrow keys, then press Option ⌥+Return ↩.

To un-minimize a specific window, navigate to the window you want with the arrow keys, then press Return ↩.