Bukkit

Teleport players to spawn/hub/lobby upon join!

A minigame similar to "Woodchips" or "Marco Polo"

PerWorldChatPlus

Brings the game "Cops And Robbers" into minecraft

Report the rule breakers and cheaters!

BetterMessages

plugin that adds commands to show links to websites

SmartDeathMessagez will disable death messages and pm the killer and victim.

SmartMessagez will broadcast custom join and leave messages as well as other messages.