Bukkit

LockOutMode Is A Plugin To Put Your Server In LockOut Mode.

Le' Ban Hammer

ProfessionalWarns

A plugin that stops session stealing and logs griefing.

A plugin to prevent the banning of certain players.

A plugin thats lets you lockdown your server in an emergency.

Invisibility Potion Block

The solid and complete anti-grief system.

Build towns!

BlockIt - The Block Banning System

Curse

FixBugs Minecraft 1.8.*

Modbot

Deadlyfe

Greylist, a simple solution to griefing. Not an open server, nor a whitelisted one. Halfway in-between.

On demand player information

DontUseThat

Because normal muting plugins are boring: Troll your server's trolls back!

Its Just a Dustbin :P

Stop those pesky Planet Minecraft "Reviewers"