Bukkit

A skills system for Bukkit!

BeTheMob

Create customized, automated poker/blackjack tables and play with your friends!

Quest World 2

A World-Generation Plugin that creates and manages space worlds.

From the Reddit thread for Miner Apocalypse, prepare to be utterly alone.

Adds blood effect for all hits!

Classes, Skills, Experience, Damage System

RocketBoots

LuckyBlocks

An unbreakable pickaxe with 20 levels (POG), which improves level by level !

MarriagePlus

BagOfGold is an item based Ecomony

Mario WorldCraft

New guilds plugin! NovaGuilds!

Make statues for your players to enjoy.

MoArrows

Advanced and highly customizable Spleef plugin for Bukkit

An extremely efficient way of economic balancing, allowing poorer players to have a chance to earn.

The Bukkit implementation of the Flint minigame engine