-Mario and Luigi: Superstar Saga: GET THIS. NOW. It's not too difficult, is very fun, quirky humor, unique control, great bosses, etc. My only problem is that it's a little short for an RPG (average 16-18 hours), but it's not to bad. Great game, trust me.
-The Fire Emblem games seem good (though they're not my personal style).
-Final Fantasy I and II: Dawn of Souls
-Kingdom Hearts: Chain of Memories
For DS:
-Castlevania: Dawn of Sorrows isn't exaclty what you'd expect of an RPG, but still VERY good (I just noticed something: Dawn of Sorrows = DS!
)
-Mario and Luigi: Partners in Time
-Final Fantasy II, perhaps?