So, I'm doing a little bit of research in a game-development sense and I wanted to poll fellow fans of the Final Fantasy franchise about some game and/or story mechanics found in various installments. I'm curious as to what mechanics people felt strongly about, one way or another in a solid JRPG.
It can be really any gameplay mechanic, large or small (minigames, battle systems, class/job systems, guest characters, secret content, loot systems, endgame battles, etc.), and for any title in the series, but please mention the appropriate title and feel free to explain why you like it or why you absolutely hate it. It could be anything that's not the actual story writing, but it could be what

