I dunno if this is useful, but for example, two of Legend Entertainment's games came in two versions:
Death Gate
- Floppy version: MCGA graphics (256 colours, 320x200 resolution), MIDI music
- CD version: SVGA graphics (256 colours, 640x400 resolution), MIDI music, animated cutscenes, with voice acting
Shannara
- Floppy version: MCGA graphics (256 colours, 320x200 resolution), MIDI music,
- CD version: MCGA graphics (256 colours, 640x400 resolulotion), MIDI music, animated cutscenes, with voice acting
(May I point out here that actually all of LucasArts' adventure games from the nineties had two versions? One of them had either lower quality graphics, or the same graphics with no voice acting while the other had a lot more stuff in it, due to the larger capacity of a CD compared to a floppy disk... or am I talking about ripped and non-ripped versions/cracks?
Whatever the case is, if I'm correct Monkey Island 1 surely had a CGA and a VGA version, the main difference being while the first had inventory items written in text while the other had the same graphical quality of MI2.)
Wizardry:
Now these had trillions of conversions, since they were popular back then.
Wizardry Collections
I won't list them in detail here, check out the link above for more info.