The easiest raid boss of each expansion?

[Dangg]

.....Lol.

BC: Gruul

And Lol at you too for naming Gruul.

[Grantley]

The easiest 40 man boss in ye-olde-Vanilla was Golemagg.

Lucifron was hard to heal. Magmadar required fear wards and tranq shot rotation. Gehennas needed a split raid. Garr blew up the dps. Geddon blew up everyone. Shazzrah was hard to tank. Sulfuron and Domo required planning and coordination. Rag had problematic sons. But Golemagg? Piece of cake.

[icausewipes]

vanilla - no clue
tbc - no clue
wrath - no clue
cata - did not finish it but nef was pretty easy.
mop - Durumu the Forgotten is cake.

[Noorri]

Vanilla: Didn't play.
BC: Chess Event. Seriously... people soloed this when it was current content.
WotLK: Noth the Plaguebringer. You basically could not wipe on this unless your dispellers was asleep.
Cataclysm: Morchok. Only people I saw dying to this boss was meele who tried to tank the black blood with a cooldown.
MoP: Jin'rohk. While having several mechanics that can wipe the raid quickly, the damage and healing numbers required are really low when you are doing it right. Too bad they didn't continue with bosses that are more like this one and less like Horridon when it comes to number tuning.

[Deleted]

Vanilla - didn't played
BC - can't remember much but Void Reaver (aka Loot Reaver) was pretty easy. Trash before him was ugh but the boss itself not.
LK - Flame Leviathan. Easily soloable at lvl 80, by any class (vehicle fight). And boat in ICC ofc.
Cata - Morchok. And Majordomo Staghelm in FL.
MOP - Normal Spirit Kings. Almost like trash with epics. Heroic was a diffrent story though :P TES normal was pretty darn easy too. Elite mode, really?

[Ryve]

Pointing out chess was soloed in BC... Wasn't Atramedes soloed a couple of weeks into FL?

[Olrox]

Vanilla - Lucifron or Gehennas I think; maybe Onyxia.
BC - Attumen or Shade of Akama.
Wrath - Almost certainly regular Sartharion or Gunship
Cataclysm - Morchok
Mists - Outside of an instance? Sha of Anger. In one? Protectors of the Endless were far easier than any other boss in the other instances.

[Noorri]

Pointing out chess was soloed in BC... Wasn't Atramedes soloed a couple of weeks into FL?

He was, but only because the air phase was bugged and the only class that could do it was a Hunter.

[Alhoon]

Didn't raid in Vanilla.

Loot Reaver
Almost any boss from Naxx
Morchok
Jin'rokh

[Deleted]

Vanila: Bat boss
TBC: Chess event.
WOLK: loot ship
Cata : Did not raid
MoP: only done LFG so i can not really comment on it

[Deleted]

Vanilla: Was'nt high enough at the time
TBC: Attuman
Wrath: Ignis
Cata: Morchok
Panda: Protectors

[Deffry]

Vanilla: Venoxis
TBC: Voidreaver (There is a reason why it was nicknamed as Lootreaver)
WotLK: 10m Patchwerk in Naxx 2.0
Cata: all BH bosses in general was ...
MoP: don't know

[Volitar]

Hmm I would say Garajol. There is nothing hard about that fight you just need to not get the worst RNG possible to kill it.

[Deleted]

Vanilla: Golemagg the Incinerator
TBC: Shade of Akama
Wotlk: ICC Gunship
Cata: Morchok
MoP: Gara'jal the Spiritbinder

[Arbs]

Vanilla: Garr
TBC: The Lurker Below
Wrath: Archavon the Stone Watcher
Cata: Morchok
MoP: Gara'jal the Spiritbinder

---------- Post added 2013-06-05 at 08:15 AM ----------

Gruul? Really?

And Lol at you too for naming Gruul.

Gruul was easy for some guilds actually, after learning the mechanics it became a cake walk.

[Krolikn]

MoP: Protectors of the Endless

[lopk]

I'm surprised with the lack of Patchwerk for WotLK. Other people are saying Leviathan and Gunship mostly, but I've wiped so many more times on those than on Patchy. :< Oh well, I do suppose that this is an opinion thread.

[Deleted]

Vanilla - Never raided extensively
BC - Chess
Wrath - Gunship. In regards to actual bosses, probably Noth.
Cata - Morchok, easily.
MoP - Either Spirit Kings or Jin'Rokh

[RoKPaNda]

Vanilla: Bat boss in ZG.
BC: Not sure, for us it really felt like Gruul though because we 2-shotted him while we wiped a bunch to Maulgar, but if we're counting Karazhan then Attumen.
Wrath: Sartharion. By far. Two weeks in and we killed him with a group of 6 people.
Cata: No clue, the extent of my raiding in Cata was getting carried through Firelands heroic by a friend's guild.
MoP: No clue.

And just for funzies, the easiest tier end boss of each expansion:

Vanilla: Ragnaros. We spent a much smaller amount of time wiping on him than we did on any of the other end tier bosses in Vanilla. Not saying he was easy, just easiest.
TBC: Illidan. Down in one day of attempts, very disappointing end to that tier. Pretty much instant farm status.
Wrath: Whatever you want to consider the last boss of the first tier in wrath.
Cata/MoP: No clue.

[khalltusk]

Vanilla - Going to say first boss in UBRS. UBRS was 15man and hence a raid! IF you want 40man then any of the MC bosses aside domo/rag.
TBC - Maiden of virtue in Kara. She was so easy when we first ripped her a new one.
Wrath - Any boss in Nax 2.0 aside last 2 who had some difficulty at least in 25man mode.
Cata - Magmaw. I went frost on normal mode in our 10man raids on my DK. We got the achievement for no parasites. Really easy boss (heroic was a lot better) Halfus on normal modes a close 2nd (his heroic mode was SO much fun)
MOP, Sha of anger purely because he got zerged.

For funzies like the guy above.

Tier bosses per expac.

Rag in vanilla, really easy compared to Nef/cthun
TBC - I can't really compare prince in kara to any of the bosses in 25man, So I will just do 25man I would say out of all of them probably illidan he seemed a lot easier than kael/vasjh and certainly not as hard as KJ
Wrath - KT in Nax 2.0 as he had no hardmode.
Cata - Only did 2 tiers and one was on LFR so I won't count it. Would say alakir the easiest on normal mode. Nef being harder and cho a close 2nd.
MOP - only completed LFR so far as i've gone casual and not finished TOT yet so will say sha of fear. He seemed so boring and simple on LFR compared to will of emperor/queen in hof.