Bukkit

Vault is a Economy/Permission plugin for hooking into the various Economy and Permission plugins.

WorldGuard

A collection of useful commands and features for server admins and players.

The essential plugin for Spigot servers.

Plugin Manager For Bukkit

A plugin which teleports you to your set home.

A simple homes with the ability to create, delete, and teleport to many different homes.

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.

Allows server admins to easily modify how Minecraft works without programming anything

If you've ever used the VeinMiner mod for minecraft Forge, it has now been recreated for Bukkit, CraftBukkit, and Spigot

An mcMMO themed plugin for horse role-playing.

Tablist

With this plugin you can cut down an entire tree by breaking the bottom part!

Remove lag and improve the performance of your server significantly with this tool!

Enchant any item with whatever you want, add lore to items, rename items too! UberEnchant has it all!

Change your ingame skin

Change the colour of the server chat!

Very configurable Tree Capitator plugin. Forest-friendly reeplants! Now better than ever! Check the new updates.

SetSpawn

Mobs will be teleported up until they are no longer suffocating