This thread gets the seal of approval from the 12-year-old me, circa 1987.
Solaris -- such an underrated Atari 2600 game! Love it, one of my favorite games of all time (says she who wrote the review of the game for this very site). Shooting pink flying crabs was never so much fun!
Tutankham -- for the dungeon crawler fan in me, and for all the hours spent playing it in my youth.
Keystone Kapers -- one of Activision's fun efforts (among many, as the choice was a hard one to make). Strangely enough, I didn't know this game until Activision Anthology came out.