I downloaded Mario RPG and got my first taste of the game about an hour after it was released via Virtual Console. I've gotta tell ya, it's quickly become one of my favorites games of all time. Admittedly, it is rather easy, but I feel that's one of it's charms. It's the perfect blend of Nintendo's platformer-design skills and Square's mastery of RPGs. I've played every Mario RPG, and the only one I can honestly say I dislike is Mario&Luigi: Partners in Time for the DS.
For only 800 Wii Points, I'd download this right away, especially if you enjoyed either of the two Paper Mario titles (not counting Super Paper Mario, as I don't really view that as an RPG, per-se).
It started the whole "time button presses to deal more damage/reduce damage you receive" deal that the Mario RPGs exhibit, and unlike most turn-based RPGs, different weapons actually play differently. I personally can't wait to battle a really cool secret boss, who I'm not sure whether or not could be considered spoilers, despite holding no significance to the game's plot.