With these sorts of numbers I'm down buuuuut...
survival clan wars/gangs server
...while this would be extremely cool it needs NUMBERS. Like consistently 10-20 on at one time in prime times (varying timezones won't help us either).
If anyone watches any Minecraft Youtubers that were in How To Minecraft S3, that's a model I think could work. Split the people in half at random on a world with two massive islands (or something, but passage across is limited, is the point). No friendly fire, resources (mostly) communal. How it works is everyone cooperates and in that series there was a mod where mobs were
crazy so you'd have to be working well together just to survive. There'd then need to be a measured way for the teams to compete, moreso than in that series where pre-organised fights and ambushes with no gain other than wagers/loot were all the real competition.
Just a thought if people like the idea of something as above. Or we could just do one no-PvP survival world where we build cool shit.