I think there is none so lets get this started!!! as for me I'd like to suggest:
1. new power surge event -less energy more play time
2. spread the love event- event for valentines day! monster drops more hearts ( I dunno why but what the heck) and tokens for a cupid's crossbow gun
3. New Year event- some enemies drop new year token for a fire works kind of bomb
4. Easter event- easter token for easter bomb
5. Haven Invasion- at a certain day on a certain time on a certain channel, that channel will be locked and npc will dissapear, gates will be locked and knights will be on fighting pose!!! lots of enemies will be invading haven!!! when you die, you can revive by energy or by waiting how many hours then the boss would appear XD, spawning monsters and jumping from channel to channel... You can only see your health bar though and players can revive you ^_^ for crowns and for mats (c'mon!!! its only for one day!!!)
6. Wolver rampage! event : wolvers will appear on every depth (with some enemies)
7. crown surge event: monsters,chest drop more crowns
8. Halloween event: monster drop (or boss) some candy tokens change for some headless horseman armor (pumpkin helmets and noble clothes FTW!!!)
I really like the Invasion concept - the idea of using Haven as a combat level has a certain appeal to it, and it fits with the in-game lore (I mean, surely the Gremlins and other Clockworks inhabitants are going to get sick of the Knights' constant invasion of their territories eventually?). It might even make a good post-Core event for high-level players; parties get transported to a unique Haven variant and have to fight off waves of monsters.