I chose:
Events where the problems are rather common, from ordinary people. Nothing epic and that 1-5 characters can solve.
These are fun because it gives the feel of just one or a few GMs kicking back and having some fun. No real plan or script is needed, just a character's motivation and a bit of a set up.
Events where the history of Yliakum is changed like the crystal eclipse events, where dozens of players can participate.
Well, I obviously like these, since I wrote some of the Eclipse events (the Garden and Dark Crystal dual events, and the Dark Wanderer side events). I like that you can feel like you are making changes to the world. And they are hella fun to write.
Events in episodes that span over several days/weeks (like the riverling event).
These I like the most, but they are the hardest to pull off. In these, you have to get the players to interact with each other, rather than a GM while the GMs are offline or in between 'events'. These are also the most closely related to player roleplay, which are nothing more than 'events' that follow your character as you play and interact with others.