Diablo was windows-based, not MS-DOS I think.
I'd say, in no particular order:
1) Prince of Persia 1
2) Doom 2
3) Monkey Island 1
4) Phantasmagoria 2: a puzzle of flesh
5) Revenge on School
+1: Fallout (I can't truly believe it was DOS,no matter how many list lists it as such, like this:
https://en.wikipedia.org/wiki/Index_of_DOS_games_(F))