My second Pokemon game, and a particularly fun one since you had to fight Team Magma AND Team Aqua. That was pretty dramatic for 14 year old me.
One of my all-time favorite games, Emerald was as close to perfect as a GBA game could get.
A solid game. The story, regions and pokémon never feel tired in this game, and adding abilities was pretty cool too. An unforgettable experience! (Although the strict assigning types to either sp. atk or atk was a bit offputting)