I would like to add control-g to the list. It is frustrating for new emacs users that it can be easy to get stuck. Control-g is the general "quit" which will get you back to editing text from most annoying situations.
ESC ESC ESC (translated from <escape> <escape> <escape>) runs the command
keyboard-escape-quit (found in global-map), which is an interactive compiled
Lisp function in ‘simple.el’.
ESC ESC ESC (translated from <escape> <escape> <escape>) runs the command keyboard-escape-quit (found in global-map), which is an interactive compiled Lisp function in ‘simple.el’.