Bukkit

PreciousStones

Inexpensively protects your ores from cheaters.

CrazyLogin

a feature-rich world size limiting plugin, which can also generate or trim a world to your border

Protect and lock Chests, Furnaces, etc. with a easy to use GUI.

PlotSquared

EntityManager

Advanced /vanish plugin which makes other players think that you're not on the server

Nerf those creepers

Player property protection using special block placement.

The premier long-range map editing tool for Minecraft SMP.

Repairs Creeper and TNT damage after a while, and much more!

Adds magical runes to the game for Teleportation, Construction, and Combat

Become truly invisible in Minecraft. Zero traces. Full control.

Stables provide steed protection, and other horse related things.

Advanced secure for region from WorldGuard

Hide from your players! Invisibility for the distinguished gentleman.

Residence

Guilds, war, land claiming, and user-controlled antigrief

A Fully Customizable Ban Manager for your server.