[quote name='Chacrana']Of the FF remakes, I've only played IV Advance, but it was excellent so I second that recommendation. Golden Sun, however, was awful. It's one of the most mediocre RPGs I've ever played and I'm convinced that the only reason anybody cared about the game was because it was one of the first RPGs on the GBA.[/QUOTE]
I thought both Golden Sun games were excellent. They weren't quite up to the level of the FF games, but they're definitely worth the money and the time you'll put into them.
Other than that, there are tons of good RPGs on the GBA--Tales of Phantasia, Riviera, Fire Emblem, all the Final Fantasy games, the Breath of Fire remakes, Mario & Luigi...
The DS is somewhat lacking at the moment, but FFIII and Partners in Time should keep you busy for a few weeks, at least.