l0rdtr3k: And why have I forgotten about Blue Force?
In an amusing coincidence, I was just thinking about that game as I clicked on this topic. I remember it fondly, though I'm not sure why - I never got very far, and it doesn't seem like it was very interesting. I guess it's nostalgia then.
Anyway, instead of reiterating what has already been mentioned, I'll throw in
Lost in Time. It was made by Coktel (probably best known for Gobliiins) and published by Sierra. I played it when I was pretty young, and so I never got very far (a common thread for most of the adventure games I played in that period), though I did remember the exact location where I got stuck, as well as the solutions for the previous puzzles. This made it much smoother when I (re)played it a few years ago, to completion and to my own surprise.
Oh, and how about unreleased stuff? Here's some [url=https://en.wikipedia.org/wiki/Warcraft_Adventures:_Lord_of_the_Clans]Warcraft[/url] for you.