If frequently opening files with other programs than the default one then one can modify the registry so the "Open with..." option is available at right clicking without needing to hold the SHIFT-key down:
Note that you might have to delete this key unless you want two "Open With.." when right-clicking a file with unknown type:
[HKEY_CLASSES_ROOT \* \shell \openas \command]
@="Rundll32.exe Shell32.dll,OpenAs_RunDLL %1"
Related Configure file types to include your own useful actions
[HKEY_CLASSES_ROOT \Unknown \shell \openas]
Related Open files of an unknown type with notepad