It's been a long time since I've been into this, so my tastes might have changed.
But my favorites were:
Photopia, 9:05, and I-0 by Adam Cadre
The Enchanter trilogy. My first introduction to Enchanter was actually this unofficial sequel: https://ifdb.org/viewgame?id=x6ne0bbd2oqm6h3a, which I loved.
Slouching Toward Bedlam: https://en.wikipedia.org/wiki/Slouching_Towards_Bedlam
If you like Zork, "Janitor" will make you laugh: https://ifdb.org/viewgame?id=utic1iedvvnnsf3a
Also have very fund memories of Humbug and Jacaranda Jim (wow it took me a very long internet search to find the names.. I forgot almost everything about what those games were about, and all I had to go on is that they were DOS executables and that the author was some anti-virus author).