I have been thinking about what i think would be a good server.
-Blocks should take longer to mine if you not owner (stonebrick castles actually practical instead of weak as [censored])
-No rules aside from no hacking
-99+ player capacity
-players can team up and create realistic societies and make their own rules and enforce them with an army or police force
-a mod to check player inventories with craftable tool
-custom skins (see the persistant kingdoms server for example)
-the throwing mod that has crossbows and arbalests (no more machinegunning arrows)
-the chat mod on persistant kingdoms but no global chat unless you have a cell phone (expensive) item in inventory
-cell phone would have durability and be recharged with mese
-good realistic gun mod
-vehicles mod but make the vehicles super expensive to reduce lag (more expensive = less laggy machines)
-horses and animals mod
-3d armor and xtra armors mods
-some incentive for players to stay on more time in a row (every x minutes in a row on some "xp" award to upgrade tools maybe)
-realistic ore distribution and more stones using biome registration (certain stones in biomes spawn with certain ores eg. granite with gold specks can have gold ore generated in it and the granite with gold specks itself generated using biome function)
I think the players making their own rules and realistic "virtual societies" and enforcing them with police force and army would be a good server, the chat limit would also mean until player can get a cell phone they can send players as messengers on horseback to send messages to other cities, no rules also means unrestricted wars and players could get a chance to take over the server, then players can resist or rebel if the ruler is too mean just like real life.