McMMO!
Friendly staff who have admin'd and mod'd a SMP server before
Zero tolerance for griefing
Custom web-based tools to keep griefers out and find them if they do sneak in
Lockable chests & doors for all players
A global interface-based shop
Player-run chest shops
Protections to keep your buildings (but not you...) safe from explosions, fire spread, endermen, etc
A starting spawn town to explore
A starting city to settle into, sell from, etc
Several hubs spread around the map, connected via a convenient teleportation network so you can build in the environment you like best
A ranks system that lets you gain perks (and maybe responsibilities) as you grow with our community (or donate toward server costs)