Sundog is a sci-fi strategy/RPG/adventure game designed by Software Heaven (aka FTL – the makers of Dungeon Master), and is generally held in high regard. It originally came out on the Apple II in 1984, then later converted to the Atari ST in 1985.
I have to admit, though, that Sundog is a touch too archaic for my tastes. At least in terms of wanting to put hours into a game. The Atari ST version certainly looks better than the Apple II version, though.