Bukkit

Create customizable chat channels.

This is a plugin that will automatically kick and the ban players.

Fakes ingame-messages like OP or game mode!

a GUI for your CraftBukkit (for Windows)

Create unlimited tutorials for all your needs! Unlimited points! Free!

NoClip through walls while in creative!

Nominately

CustomBanMessage

Restricts the end and nether for people without permission

You heard right, no client mod required!

Warns admins if a certain block is placed/destroyed.

iWarp

BlockEnderDragon

Comprehensive Anti-Cheat plugin that is centered around catching cheaters and remediating them

Adds Brand New Weapons!

AutoForceCommand

Authenticates clients using an RSA certificate

Control the use of TNT and Bedrock

Fun & admin commands such as disguising blocks and glowing items!

WorldGuard Instabreak Flag