I'd really like to see a deathmatch server with multiple builds that get loaded in sequence, where each one is a different era/theme with weapons for each build.
So it could have Cavemen with clubs, throwing stones and flint axes in a cave-filled forest.
Then Romans with bows, gladius swords and daggers in a Roman city.
Then Medieval europeans with longswords, pikes and longbows in castles.
Then Pirates with cutlasses, flintlocks and muskets on ships and a treasure island.
Then WWI, with rifles, pistols and dress sabres in trenches and no mans lands.
Then modern warfare with assault rifles, snipers and grenades and knives, wherever.
Basically a DM server with variety in weapons, theme and gameplay.