Bukkit

EnchantExtreme - Extend Your Enchantments

Fortune enchanted Iron and Diamond Pickaxes affect Iron and Gold ore

A parkour+ type plugin based off of Assassins Creed

GlowTree

Adds Explosives to your Minecraft Server

Adds multiple arrows that the user can craft and use.

Add Scopes To your Bows!

aSign

A zone based player/mob detector system with wireless redstone triggers (Advanced users)

UltraHardcoreMC

Gives players set number of lives

Links the experience system with your economy plugin.

Storages for your Boats and Minecarts

DuelAnnounce

Rotates through a list of scoreboard objectives on the sidebar

A light-weight plugin which allows for the claiming of doors via command. Doors can also allow for specific people to open and close claimed doors.

A simple homes plugin

GuiRedeemMCMMO

Textile

Makes Ingots and Nuggets into Blocks