As far as the GBA Goes, you can't beat Golden Sun. It's large quest and intersting Djinni system will keep you hooked for hours. Camelot did a fine job with their first RPG.
One of the most impressive things about Golden Sun is that the graphics look like an N64 game. Vivid, easy to see colors and smooth edges manages to beat out any other GBA game to date. It seems like this is the first GBA game to actually take advantage of the fact that it is a 32-bit system.
And those wonderful looks comes with a great soundtrack. Slapping on a pair of headphones will make you feel you are playing the game in front of a full-scale orchestra. Seriously, it's that crisp. Psynergy doesn't sound realistic, but is still very clear. About the only thing missing from the sound effects is the noise of your footsteps.
Technicalities aside, Golden Sun delivers with flair. The innovative Psynergy/Djinni system isn't the easiest thing to understand, but it's not like FF VIII's Junction system. Being able to trade and set Djinni to obtain new spells definately adds loads of strategy. Battles are fairly simple; as in the old Final Fantasy's, you choose each action of the charectors before the attacks are carried through. Each charecters speed is different, which adds even more strategy to this game. My main gripe is that using and Setting Djinni alters your stats, and can make you more vulnerable to enemy attacks. But other than that, Golden Sun is near Perfection.
Well, except for the story. Sure, it is quite an epic tale, with kidnappings, twists, and nations in turmoil. But sometimes, Isaac and company just won't shut up. They can blab on for 10 minutes straight about the silliest things. And it happens before battles against Menardi and Saturos (which are rather difficult battles). Death means you have to live through the pain of blah-blah's again. If it wasn't for this fault, I'd give the game a 10. But, alas, that is not so.
Other than the 20,000 page script, Golden Sun is one heck of an adventure. Any RPG nut, or GBA owner for that matter, should include this monstrous game in their library. Let's just hope Camelot doesn't abuse the story in their next run.