Bukkit

AntiBadWord

flexible, powerful, yet simple chat management

SkittlesChat is the simplest, most effective per world chat plugin!

Block any command from players who aren't on the plugins Admins list.

FuginBoxFoundInfo

This is a plugin that allows your prefix to be your current balance!

NextLogin is a multi-language authentication plugin for servers.

AntiAdvertiser is a configurable plugin that lets you keep your players.

A comprehensive chat-management plugin.

A plugin with stuff (commands) that might be useful I think

Levelname

GenuinePromoteMe

A simple private messaging plugin

The ultimate player punishing plugin!

imRecoding Plugin by : 6alalGamer

BetterSay allows you to put a custom prefix at the /say command.

Light-weight plugin to disable Login, Logoff, and Death Messages.

The best PvP Stats plugin, simple and easy to use!

AltChecker allows you to see a player's IP and all accounts that have logged into your server with the same IPs.

Shout announcer