Oh right, that part...

[NoeL]

Although I haven't actually replayed it, the thought of collecting those Tadtones again in Skyward Sword often keeps me awake at night.

 

[Thandran]

Tri - Force pieces hunt in Wind Waker. God. Damn. Boring.

Could've used another dungeon or two, but nooooo.

 

[kickyourass]

Dragon Age: Origins, I want to preface this by saying, the whole rest of the game is wonderful, this is one of my favorite games period, hell the rest of this section of the game is pretty ok, BUT whenever I reach The Fade in the Broken Circle quest, I want to find the section of the dev team most responsible and beat them about the head and shoulders with a wiffle ball bat.
It won't kill them it'll just hurt like hell. A long boring series of puzzles, a stupid as hell transformation mechanic that serves really no purpose other then to complicate it needlessly, a camera filter that honest to god gives me a headache if I play for more then half an hour, it's just this huge shit stain in an otherwise fantastic game.

 

[Last Hugh Alive]

Red Dead Redemption and GTA IV. I still love Rockstar games but man do they usually seem to begin so slowly.

Also, I often have doubts about playing Metal Gear Solid 2 again for the escort mission and the bombardment of cutscenes.

 

[Scarim Coral]

Phantasy Star Online Episode 2. The Olga Flow boss (that boss is so hard that I competely put off from fighting him altogether no matter what rare loots he drops).

 

[PH3NOmenon]

Irenicus's Dungeon. The very start of BG2.

Played so often it drives you mad and the longbow goblins just drive you up the wall.

 

[MetalMagpie]

Dragon Age: Origins has two. Wanna take a guess? The Deep Roads and the Fade. The Deep Roads just take forever to complete and are just boring, the Fade... well if you've played it you know why, boring puzzles and a stupid transformation system to name a few. Possible the fact it should never have existed.

A million times this. It took me over a year to complete my first (and currently only) playthrough of DAO, largely because The Fade took me weeks (playing a little bit every now and again) and I ran out of patience entirely midway through the Deep Roads and didn't play the game at all for eight months.

 

[Flaery]

Silent Hill 3, the fuckin' hospital. The slurpers, so many slurpers, and I refuse to drop down to easy difficulty.

 

[Hades]

Orthan taig from dragon age Origin. I hate how many spiders you have to fight in that place.

I also hated the lightning temple in tales of Symphonia.

 

[Longstreet]

Mass Effect 3 - the ending

In all seriousness, i just can't replay Skyrim / FO:3 / FO:NV. I think this is due to the fact that 1) I know the first few quests by heart now. And 2) because you have to start over.

 

[Lieju]

I was just replaying Ace Attorney: Trials and Tribulations, and I had forgotten how much 'Recipe for a Turnabout' annoyed me. Especially the first day. I'm not usually bothered in that series when I have to try guessing how the game wants me to get across my answer, but there was way too many moments where I just wished I could yell "WHO CARES IF IT WAS LEFT OR RIGHT!? HOW DO YOU EVEN REMEMBER SOMETHING LIKE THAT AND WHY ARE WE ACTING LIKE THIS IS A RELIABLE TESTIMONY!?" at the court when cross-examining Kudo and Armstrong.

 

[Greg White]

Most of Lost Izaleth in Dark Souls because screw the dragon butts, they were just annoying, screw the Bed of Chaos because it's not even hard, just annoying, and screw those damn bugs for making Solaire crazy.

Any water levels in just about every game ever, especially Mojaro's Mask.

 

[Mobax]

I can't think of a specific game where there is a part I don't ever want to play again. But what does annoy me is games where it takes an extended un-skippable amount of time to start a new play-through/character. Fallout 3, Skyrim, Oblivion were all bad for this, or fps games that force you to do the "learn to shoot" mission every time. Fortunately I rarely replay campaigns on fps games. But for games that are single player based, those un-skippable intros become so annoying. At least in Oblivion you could save right before exiting the sewer, and therefore could load that save up, still change all your character info then exit. And Fallout 3 had something like that, except you could make some decisions in the vault prior to leaving that have repercussions later on. Skyrim is the worst for this for me. I have a save before the legion calls your name to be executed, so I can load that to skip the opening wagon ride sequence. However, I still have to do the entire run from the dragon, fight your way out the underworks. Even speed running it, it still takes 10 minutes. It's really annoying, since I enjoy making new characters from time to time.

 

[votemarvel]

The only one that springs to mind is "The Fade" in Dragon Age: Origins. Thankfully though even that isn't an issue any more thanks to the Skip the Fade mod on PC.

 

[KarmaTheAlligator]

Atlantica and the Pride Lands in Kingdom Hearts 2. Love the game, but I really dislike those worlds. At least Atlantica is easy, if annoying.

Oh god. I remember I put my TV on mute for that part. I was embarrassed to be playing it even if nobody was around at the time.

It's not so much embarrassing as the first song you have to do (swim this way) is horrible. At least most of the others sound like they're from the movie so if you don't mind that, it's fine.

 

[Quoth]

World of Warcraft levels 85 to 90

 

[Tyrant_Valvatorez]

One that comes mind is Zack's side quest in Megaman Starforce. With the exception of the SP form of the post game secret boss and perhaps trying to S-rank GeminiSpark SP, the game is laughably easy and its like the developers thought "hmm the game is too easy what can we do?" "Oh I know lets throw in a gauntlet battle with no health recovery!"

So you get that one side quest that is more frustrating that hard since the enemy combinations are deliberately set up to make avoiding damage difficult, no health recovery and one enemy that is immune to everything but sword type attacks. If you get one bad draw of battle cards at any point its time to restart the whole 10 fight slog again! ... so fun.

 

[Woodsey]

Red Dead Redemption and GTA IV. I still love Rockstar games but man do they usually seem to begin so slowly.

They have no concept of pacing, and it won't be solved until everyone stops pretends they're the gods of storytelling. Almost the entirety of Mexico in RDR is filler.

I hope they learn not to outsource boss battles ever again. Seriously.

The one in The Missing Link is genuinely good.

 

[Tom_green_day]

Loads of games have tutorials that really bore me or put me off. Borderlands 2, Red Dead Redemption, Fallout 3, every Mass Effect game, Skyrim etc. Holy hell, they are enough to put me off replays.
EDIT:

In all seriousness, i just can't replay Skyrim / FO:3 / FO:NV. I think this is due to the fact that 1) I know the first few quests by heart now. And 2) because you have to start over.

I used to feel this way, and being an achievement whore means for Fallout 3 at least I had to replay the game to get all the achievements which was hell-as boring. However, once you get past the GNR/Rivet City part of the main story you really get to like the game again, I found at least. Also you try stuff you never did in the main game, like I now have Clover as a follower who is actually pretty good, and actually use melee now instead of selling all the melee weapons. At least you can platinum Skyrim in one play-through.

 

[Thyunda]

The portal puzzles in Darksiders put me right off replaying that one, the Big Daddy sequence in BioShock and the constant Little Sister protection in the sequel.