If we mean literacy...

While tons of people have mentioned Star Fox, Super Mario Kart, Super Metroid, Final Fantasy VI, Earthbound, Zombies Ate My Neighbors, Chrono Trigger, and Donkey Kong Country, Super Mario RPG, I will try to submit some other titles, as you were asking for games required to be literate.

1) Street Fighter 2. Guile's theme goes with everything.

2) Final Fantasy 2/IV. With far more translation errors than 3/VI, the game is still absolutely classic, with emotion and beautiful music and plot twists.

3) Mortal Kombat 1/2. The first is a necessity, but the second gives the true spread of characters.

4) Secret of Evermore. Not necessary for literacy but one of my absolute favorites


Honorable Mentions: Final Fight, Ogre Battle: March of the Black Queen, Disney's Aladdin, Final Fantasy: Mystic Quest, Super Star Wars (all 3), Illusion of Gaia, Super Bomberman, Castlevania (pick any Snes number, but I loved IV), Act Raiser