Transition patch specs are NOT listed! Blizz cares less about balance in these patches so it isnt fair to put them on the list.
So everyone knows that there have been times where a certain class has gotten out of hand in PvP. These times are usually marked by that class being marked as faceroll, and massive people rerolling to destroy all competition. But which class has been the worst? Which class/spec in all of WoW history has been so powerful that it will go down in history as "most OP ever!" Here are the rules. The classes/specs will not be chosen if they are in a transition period between an expansion (like now). This keeps people from just tunnel visioning on todays imbalances...AND keeps it more interesting, as pvp balance is more important when a pvp season is taking place. Here are the choices and why.
(Vanilla WoW) Rogue - Prep resetting blind and and coldblood guaranteeing crits let rogues stunlock you from 100-0 without much you can do about it. If you didn't play vanilla WoW...just look up the old school World of Roguecraft videos on youtube. They may be old but they are still really fun to watch.
(Vanilla WoW) Warrior(MS) - Sweeping strikes+whirlwind+mortal strike+epic loot+healer meant that this guy would walk into your BG...kill your entire team...and cause you to ragequit every time you died during a charge stun. The vanilla Warrior gets a slot
(Vanilla WoW) Shaman(Enh) - If he had a good two hander and a windfury proc..you were dead in one hit. And good luck getting away when the shaman can just keep frostshocking you into oblivion. Enh has never been as powerful as it used to be in vanilla..at least not as far as pvp is concerned.
(Burning Crusade) Warlock (SL/SL) - Ahh the memories of sitting in a fear with 4 dots on you watching a warlock that couldn't die draintank anything it saw coming. This era was so bad that you can still find a lot of Warlocks named "nerfmebro" or some other variant. Impossible to kill with decent damage gives SL/SL a spot on the list.
(Burning Crusade) Druid (resto) - Speaking of impossible to kill...These guys ran rampant during the final seasons of BC. I personally think that it was this spec alone that made the 2v2 bracket no longer give the same pvp rewards. A TON of CC...heals that cant be interrupted...and unmatched mobility made this class undefeatable in small scale pvp if you knew how to play.
(Burning Crusade) Priest (Disc) - While unable to match the fearsome resto druid in 2v2..the disc priest was far and away the healer you wanted in most 3v3 comps. The only healer able to put out decent burst with Mind blast and shadow word death made them great for landing kills. They also had a reliable CC, and power infusion to help casters. But we all know that's not why our glowy handed friends are on this list. The reason is mana burn. Being the worst nightmare to ANY toon with a mana bar..and being a part of the longest lasting best pvp team (PMR) gets our friend a spot on the list.
(Wrath Season 1) Paladin (holy) - When there was almost no resilience and paladins could become immune to everything for 12 seconds..they always were the healer of choice. In fact, they are always the healer of choice whenever an expansion has been released for this exact reason. I predict for the first seasons of Cata pvp, this spec will be preferred again (unless we really dont die in 3 globals like blizz is saying). Taking up ridiculous numbers in the start of wrath pvp on the top 100 list..we have to give this spec a slot. Im sure Athene will be proud
(Wrath Season 1) DeathKnight - Unable to be killed with high damage. Deathknights changed the pvp scene dramatically with their release. Teaming up a Deathknight and a holy paladin was like cheating in the first pvp season of wrath. That earns this class a spot on the most OP EVER list.
Absent..Mage and Hunter. Hunters sucked for almost every pvp season to date...with LoS making them almost useless in pvp for an entire expansion. They got pretty powerful with Killshot getting good, but still cant make the list because of their god awful arena rep. And mages might have had a spot when they could one shot people with PoM Pyro..but it could only be used once every few minutes and was far less threatening than seeing a warrior shaman or rogue at any point during the game.