I finished Final Fantasy I & II on my GBA-SP awhile back. Then Soul of Rebirth, which was more of a little add-on than a full fledged game. Cool games, I liked how they updated the graphics and ported it to the GBA, well done.
I then tried to pick up where I left off with Golden Sun: The Lost Age, but it was impossible to get back onto the storyline. After I got the boat, I travelled all over the world checking things out, but now I'm lost. It's a very good game, kinda like FF but with added puzzles to figure out so it's not just levelling up all the time, you need to think about what you're doing.
Frustrated with GS, I saw a bunch of GBA Zelda games on sale at Amazon, so I picked up the original Zelda, Zelda II: The Adventures of Link [both of which I finished way back in the NES days], Zelda: A Link to the Past and The Minnish Cap [never played these two]. Started playing the first Zelda and I hope to continue through the whole series. Damn, this first game starts off hard, you don't have much life! I'm up to 5 hearts now so it's getting easier. I also have two Tri-force shards and the blue ring and the bow. I might play this through at the same time from my Zelda collection on the Gamecube. The GBA edition seems like a straight port, no improved graphics or extras, maybe that's why it was so cheap.