MacAppStuff Shortcuts is a reference tool for you to quickly find the useful shortcuts (over 280 in the purchased version). The app resides in the menu bar, click on its icon to show a menu from which you can show the app's main window or quit. Shortcuts can be filtered using the 'Category' popup menu, or 'live' searched using the search box. You can add your own personal shortcut references too.
Shortcuts can be marked as favorites (check the box in the F column), and even added to the app's menu bar drop down menu (check the box in the M column) so you can glance quickly at the menu for a reference. Create and delete your own shortcut references. Print all or only a selection of the shortcuts, for paper reference.