This is an awesome thread that begs for revival.
My two faves are on the Amiga.
Nothing compares to "Lure Of The Temptress".
It's the best of all worlds; great graphcs, humor, story, characters.
And then there's Shadowgate. Creepy, alone in a dark castle, and with challenging puzzles.
I first played it on the NES, but the Amiga version did it justice.