My first GBA Pokémon game. I remember playing it for hours and hours, my savefile had more than 600 hours registered! Discovering Hoenn was amazing and always chose Torchic. I still have my Blaziken from my Ruby, it's a very old and beautiful piece of data that currently lies in my Ultra Moon. Of course later I got Emerald and prefered with that, it was just better, but Ruby remains as a classic alongside Sapphire. I sold my Ruby when I was like 16, I don't know why... I really regret that and I am considering getting it again just to have all GBA games from these series and running another playthrough in wonderful Hoenn every now and then...