AoZ is the most friendly and polished game, so most prefear it.
Still GtG was a more intense experience for me.
GtG combat is more "technical", you can't just use Generic_Attack_Move_025 to fight, but must carefully pick the correct one and proper timing for each enemy.
The sword bounces of walls pulling you off balance, gets stuck in trees; to use the shield you must precisely face the attacking enemy.
AoZ gets rid of those rules, becoming more friendly but also more generic.
Let's button smashing pass more easily. Someone will like the greater feeling of being kicking butt, but to me feels at times a little less rewarding than the more precise attacks required in GtG.
Powerups are also more satisfing in GtG, in part cause are harder to attain, and due combat being more challenging, making every trickle of power you gain more determinant.
On the other hand AoZ introduced the cool combo system, secondary characters you occasionally have to fight along or protect.
Level design is remarkable in both games for adhering to the old school of thought: A Challenge Every Step.
Doesn't attempt to create a world, which would often results in lots of backtracking and dull areas, but a well disguised and packed obstacle course to maximize the fun.
Challenge was toned down a bit too much in AoZ.
Especially at the end, the most powerful earthquake skills can clear waves of enemyes in one or two hits, while the energy regenerating boxers will let you abuse the move, maybe alternating it with Death summons - similiarly cheap once their duration is maxed. Death was more fun when it only offered a couple seconds of invincibility, than when clears areas for you.
GtG went overboard in the opposite direction with the nightmarish save system though, thankfully removed in the sequel.