Back in the day I would always read gaming magazines and they always said,"if you got a PC, get that version of the game. If you got a Mac, then you'll be happier, but if you are lucky enough to own an Amiga, GET THAT VERSION!!!"
PC games didn't really begin to pick up until the early 90's with VGA and 16-Bit sound cards. Until then Amiga was always the way to go. So ya, with Space Quest 3 on back, you'll want to play on your Amiga, then with 4 and 5 you'll want to run ScummVM or DosBOX, though I highly suggest going with ScummVM which has also been ported to every Amiga based OS out there.
As for Space Quest 4, you'll notice that the PC version has dialog all through out the game which the Amiga lacked because it had not jumped onto the CD-ROM bandwagon yet. The same goes for many of the early 90's PC ports. They had CD-ROM so they got the definitive versions of the game.
If you are a space quest fan you have to check out some of the fan made titles out there, especially Space Quest 4.5.
