If you want to play the original EGA version then you have to “find” it.
Otherwise you can get the Special Editions (GOG, Steam…) and convert them to Ultimate Editions.
Those are nearly bug-free version and you can play it with voices if you want (classic VGA graphics).
e.g. see MI Special Editions - don't work on Mac OS? - #8 by Nor_Treblig and I also mentioned it in this thread: Monkey Island 1, 2, 3 remakes! - #12 by Nor_Treblig