Secret of Mana is one of my favorite games for the SNES. It's a multiplayer co-op adventure rpg, but it's still fun as a single player game. The story features a chosen hero, a girl warrior, ancient lost technology, an evil wizard, and of course a magical legendary tree.
It features an unusual AI system for your party that allows you to determine how aggressive/passive they are. Battles are in realtime rather than turn-based, keeping the pace of the game much quicker (and painless) than the Final Fantasy games it was loosely based on.
It's a big, beautiful world - so big it's easy to get lost, but there's a convenient cannon travel system that literally shoots your party to various locations around the map! And true to the style of Square Enix fantasy rpgs, it's full of bizarre enemies (like flying books) and has an immersive, almost jazzy soundtrack. And the world map is even in globe-form, so cool!