Nice topic!
Two gems I love to death, both for the Sega Genesis: Wonderboy in Monster World and Starflight.
I remember playing WBMW on the arcade when I was a kid in the late 80s. This game looked so awesome, when I saw it for the Genesis... It's basically a side scroller Zelda.
Starflight is much like the aforementioned Star Control, you captain a ship, meet aliens, gather ressources, make friends, fight enemies and prevent the destruction of your planet. the highlight of this game: The Veloxi. Insectoid-humanoid aliens with terrible broken english who are extremely arrogant and full of themselves. I love these guys so much you wouldn't believe.
At some point in the game, you have the possibility to do a big favor to their race, becoming their new best friend. What happens when a race of extremely arrogant insect people think that you're the (second) best thing in the universe? Unending laughter ensues.