Bukkit

LoginSecurity

mcMMO

Shows TimeZones

Fully customize any mobs (and create custom mobs) with a powerful scripting skill system, attributes, equipment, special AI, and much more, along with custom spawners and spawning rules. The ultimate plugin for making RPG servers and minigames.

Lets ops keep tallys on servers

BackAgain

Have minecraft read the chat to you

BukkitGUI - the most downloaded GUI for bukkit and any other server

Have a PVP Menu to get Items

Allows Ops to record players movements and play them over again

Disguise as a mob or other player

ServerInfo

Toggles the physics within a radius of the player.

Limits amount of creater spawns via limits set by config

Lets you sell a players heads for half of their money

Adds Lotto, Loans, Stocks

A Simple way of creating worlds for LobbyAPI

A Simple way of adding Bungee Servers for LobbyAPI

LimitDrops

This is an Addition to LobbyAPI which allows the menu to show the world "world"