Bukkit

Troll those briefers and nodders!

SecretPotions

Enable / Disable damage from varius sources like Explosions, Fall or Damage by Mobs

ProfessionalBans

NoSeeBan

Social graphs, chat logging, and messages made simple!

PMan

Spawn Physical Orbs

Logs chest access and gives easy access to logs.

Ingame-quiz plugin which allows you to set up to 100 questions! Teleporting!

This is the best plugin. /[TAB] /ver [TAB] and so on, the following commands this plugins blocks 

ChatClear

including Broadcast, TeamChat, ClearChat, GlobalMute & CustomJoinLeaveMessage

More Commands and Fun Commands

Bothered jails count down even when player is offline? Then use this!

Advanced CustomBroadcast

The most extraoridinary broadcasting plugin ever!

A great plugin that enables you to create blocks that can be used an infinite number of times!

Help yourself to manage your server!

ChunkyBlocks