The top five is clear as day:
1. Star control 2
2. Star control 2
3. Star control 2
4. Star control 2
5. Star control 2
the rest, i loved dune II westwood really put in their passion which created life in the game, the atmosphere, sound, the world, the units was a perfect balance for creating an immersve atmosphere, yes space quest for sure as well, hero's quest, Rex Nebular ! monkey island, loom, kings quest, on the side i liked test drive and the game stunts (where you created stunt tracks for stunt cars)
The cnc series is good, but cannot be compared to westwood's first cnc creations which was ultimately RUINED by ea, but still i did enjoy the cnc by ea just not as much as i would've if westwood survived. the first few cnc's were really good. i like far cry especially # 2 as the african atmosphere, environment and sound was really REALLY immersive and the characters was very good, the other far cries had a feeling of disconnect, (however havent tried the himalyas one yet)
o and Of course wing commander and star wars pod racer.
o thats it...... just gotto add some more classics 
Golden Axe, Double Dragon
commander keen
ironman, that off road car racing game
rampage
ghost n goblins, ghouls and ghosts
