I am surprised that the most OBVIOUS of game collections has not been mentioned.
Who here has not played a version of SOLITAIRE from Hoyles 1 or Hoyles 2?

Also a great strategy game called ANTAGO which is virtually unknown. (Devil VS. ANGEL)
I think that it is French in origin. I come back to this one frequently.

There are so many that have merit, such as ATARI games "9-LIVES" with cute graphics, great music
and superb platform puzzle playability.
MS.PACMAN and the SUPER SPACE INVADERS kicks ass for frantic actiion and speed.

I also like BLOCKOUT which is a 3D take on the old game of pong. It has an addictive nature and
fast gameplay.

GOBLINS 2 is just a hoot and has brain teasing puzzlers as well as comic action. You get to choose
between characters and try to make them work together.

For sheer graphic beauty, GUY SPY has that quality cartoon appearance and digital sound.
I have DRAGONS LAIR 1,2,3, and 4 and love the look. Game play is something of a  joke though.
I cannot say how 3 and 4 play since they are still sealed in cellophane.