The event in pso2 was fun, they had a raid that was like a ffxiv dungeon where you fought Odin at the end of it. In fact, you can still run into Odin occasionally out in the free fields.

It would be fun if in ffxiv you could face one of the Dark Falzes as a raid boss or something (Loser comes to mind since I feel his mechs are the closest that could fit in ffxiv).