Patch 4.2 was fucking insane.
I go through phases where I enjoy playing WoW...

(Dumb accent) You Though Sephirtoh Had a lot of hp Yiazmat has 50000000000 hp

jasper batt jr is ANNOYING ANNOYING as in bratty and his third phase is........ a ballon? you gotta be kidding me

Quote from Riolu3000

(Dumb accent) You Though Sephirtoh Had a lot of hp Yiazmat has 50000000000 hp

that's "Sephiroth"

sorry

and i ment yiazmat has 50000000 hp

I hate Gabranth in Dissidia. He'll keep dodging. FFFFFFUUUUUUUUUUUUUUUUUUUUUUUUUUU!

The Phantom, I believe that was his name, he was a secret boss in Kingdom Hearts 1 in Peter Pan land. On the battle start, he puts a death counter on both of your followers/teammates, so you have to cast Stop on them, but the worst part is that if they go down by the death counter, they stay dead, no rez's. Another thing, you can only attack him depending on the color of his orb under his cloak, red = fire, blue = ice, yellow = lighting, and white = physical attacks. If you attack him with anything else, it's useless. It is pretty horrible for a person who doesn't know that information.

the last boss in shadow of the colossus. just because it was tedious and not very eventful :P
i enjoyed that game thoroughly though :D

10:death egg robot (sonic the hedgehog 2)

9:sephiroth (kingdom heart series)

8: triceratops (Joe and mac 3: lost in the tropics)

7:N (Pokemon black)

6: Dracula (castlevania 2) (without spamming the whip)

5: petey piranha (super princess peach)

4: Majoras mask (Majoras mask)

3: wither (minecraft) (survival mode)

2: mother brain (super metroid)

1: little horn (super meat boy)

i NEED to tell why i hate little horn and why its annoying. first, i know super meat boy is HARD, but little horn is more CHEAP then hard. making the game call itself super CHEAP boy. second the level you fight it it is the 2nd hardest level in the game. and its called freaking hell for crieing out loud. finally the battle itself. i LOVE the music but that's the ONLY good thing about little horn. the reason why its number 1 is that fighting him is a pain. the only thing to beat him is to memories ALL of its attacks (dramatic pause) IN ORDER. because ITS THE SAME EVERY TIME. not only this is the annoying boss in my opinion its the worst boss i ever found in my life

Maze from Fable. He's so fucking annoying.

Most of the people here says its from Dissidia. They arent that annoying, its just Feral Chaos, who has 50000 HP.... with his Demonsdance, not annoying at all.

Anyway, 2 bosses.
Yiazmat, FF12
Ozma, FF10

1. Parasite Queen (Metroid Prime) I've been stuck on that first boss for YEARS! This boss is a total drama bitch queen! It's a good thing I've finally beat her and finally got to the storyline. If you played this game before, you know how freakishly hard and annoying this boss is.

2. Dark Yabuu (Vexx) This guy is annoying as hell! I know he's the last boss, but he SO HARD TO KILL! Even if I watched the walkthrough on how to kill him, I can't even execute it right!! It's like you've studying all week for the big exam, and you somehow failed it! I've been stuck on that boss for a long time, and even in this age, I can't beat him!

3. King Bulblax (Pikmin) This final boss cost me a LOT of Pikmin! He was tough as nails to beat, and the most annoying part about him is that everytime he jumps, he manages to squish half of my Pikmin army! The only part I have to attack is his face, but his entire body is encased in hard rock or something, so that limits my expectations in taking him down.

4. Porky (SSBB) I really hate this kid! I really do! His hits is so massive that it gave me a hard time to beat it! I've always despise this SSB boss! Few of his moves are impossible to dodge and it ends up killing you in one hit!

5. Huff N. Puff (Paper Mario) What can I say about this huge-ass puff of horse-fart? At times his attacks are so massive that it was annoying to go back and try it again, not only that, at times, he can heal himself when I was almost there in killing him!

6. Magnus von Grapple (Paper Mario:The Thousand-Year Door) This guy... oh hohohohoh, this guy... before I encounter this guy, I have to rush through the whole damn tree because he activated a time-bomb (there's a freakin' countdown for it!). There's so many enemies I have to rush through and when I did get there, I have to go through the dialogue before the remaining time runs out. The most annoying part about him is when I die, I have to rush through the damn tree ALL OVER AGAIN!!!

7. Faction Champions: Trial of the Crusader (WoW) Being assigned to kill one of the champions may sound easy on paper, but once the battle starts, you get jumbled in all the commotion, causing you to lose focus on your target while everyone is running around like lobotomized maniacs! It's freakin' chaotic! This boss battle tends to wipe your raid group over and over without a solid-proof plan and a slight chance of luck.

8. Flame Leviathan: Ulduar (WoW) This hunk of junk is the first boss in Ulduar and, even though it can be easily killed, it tends to wipe your raid group by weak tanking and no planning! I put this pretty low on the list because once you've figured out all this stuff, this boss will stop being annoying.

9. Phantamanta (Super Mario Sunshine) Despite being one of my favorite and unique bosses, this monster loves to spread around pain and frustration. Literally! It starts off huge while leaving behind electric goop, but once you shoot it with water, it'll break up into mini versions of it! The worst part is that if it touches you, it'll send you flying straight to a nearby electric goo pool. Sooner or later, you'll feel like you've just became their volleyball. Though it's fun, but fall into those goops, then you're in for some real pain.

10. Big Bully (Super Mario 64) Not much of a boss, but it's an annoying boss. This giant pushover loves to push you around, hence the name Big Bully. It's annoying on how he works as if it's unfair, like if he pushes you down, he'll keep on pushing until he knocks you off the edge of the field into a fiery pit! All you have to do is push him back, and that's it.

Here's a few of the bosses that annoy me:

Gyorg (Legend of Zelda: Majora's Mask) - I hate this slimy piece of fillet. I cannot for the life of me hit him without taking damage. It was so bad that I actually turned infinite health (gameshark) on to beat it - mostly because I didn't want to go searching for 20+ heart pieces.

Golem Twins (Chrono Trigger) - I still haven't beaten these guys. They mimic your attacks back at you (you use fire, they use fire, etc.). On top of that, they have an attack called "Iron Orb" that instantly halves your HP.

Great Mighty Poo (Conker's Bad Fur Day) - While this is one of my favorite bosses of all time, the fight gets a bit tedious towards the end (you have to lob a roll of toilet paper into its mouth 6 times. 4, 5, and 6 take a few tries each, usually). And if you screw up? You start at the beginning of the song!

Also, a lot of Minecraft 'boss fights' (adventure maps) that involve a army of mobs really frustrate me, mostly due to the knockback. Getting kicked back by one mob causes brief disorientation by the player, and by the time the player reorients, he is either hit again or killed. In these cases, I feel cheated, not only because the death was cheap, but because the boss is nigh impossible now because all my items dropped in the middle of the boss room, unobtainable without getting mugged (and probably killed again) by the mobs again!

I'm surpised no one has mentioned Tabuu, from SSBB. He gave me a heck of a time trying to kill him (and failing).