Bukkit

Know who attacked you and with what they attacked with. [PVP]

PvP Shield protects players from PvP on respawn.

Allows players to individually control whether PvP is enabled for themselves

Weapons Cooldown and other features like special abilities and damages control, include spout support

Count your PvP kills and deaths

PVPRewards

Choose what ingame hours you want PvP enabled.

This plugin enhances pvp on pvp servers!

TopPVP allows you to keep track of your kills and deaths - PVP Plugin

Place a block anywhere and disable PvP around it.

A PVP and Events Manager

FightTag, a simpler way to control PVP.

ElementalWarfare adds a, rather explosive, twist to PVP!

Disable PvP in Creative mode

ForgeDeaths is a lightweight deaths plugin designed for PVP focused servers

Handle PvP for groups and players

Enhanced combat for PVP and PVE

A simple Free For All PVP Plugin.

allow players to toggle PvP for themselves

Simple flight control with many PVP capabilities.

Adds essential pvp commands and features to your server. Everything is configurable

A simple solution to PVP

PVPTracker

A plugin which nerfs a player's ability to abuse enderpearls in a PVP situation.

a PvP Bounty mercanary system