What are some particular areas in games that you think brought down the quality of a game so much that that particular game should have just removed that section in its entirety? Here are a few that I have come up with. 

Dark Souls -- Demon Ruins/Lost Izalith

Thought I was going to say Blighttown, huh? Well, while Blighttown is masochistic and a chore, it at least is interesting visually, has a great boss at the end of it, and is forgiving enough to have those awful dart shooters die permanently. But the whole fiery path of the Demon Ruins and Lost Izalith has no redeeming value whatsoever. It features an onslaught of four terrible bosses wherein the best boss is a reskin boss of a reskin boss. Not only that, but the area is so visually bland and unappealing and the enemies feel like they were just placed like an amateur would place enemies in a map editor -- randomly with no rhyme or reason. The second half of Dark Souls is a let down even without the Demon Ruins, but this trash area really just sticks in your mind.

Dragon Age: Origins -- The Fade

I don't think this area needs much explanation. I already disliked Dragon Age: Origins, but this area just put a horrible taste in my mouth.

Xenogears -- Tower of Babel

While I will admit that there is a certain mystique to the size of the area, the horrible jumping puzzles were soulcrushingly awful.

"Cortana" in Halo 3. So much Flood. So aggravating.

JRPGs - Random Encounters. Stop that.

Not an area, but the Tri Force Quest should be entirely removed in Wind Waker. It was already made a bit less tedious in Wind Waker HD, but I would prefer for it to be gone completely.

Nah, try Paper Mario.

All the platforming junk in Xenogears was terrible.  It wasn't fun and just something I wanted to get past.

In a similar fashion, Borderlands 2 Tiny Tina DLC had an awful rising floor puzzle section where you'd die instantly if you touched the ceiling.  I hated that so much.  You had to stand there and study the floor to figure out when to run through and then wait for the perfect time to come back around.  I'm not playing an FPS for that.

Far Cry.  The sections where you're drugged.  By that, I mean both FC3 and FC4.  They made my head hurt and they were bloody frustrating.  I do not understand why they are in the game.

- Battletoads - Turbo tunnel level
- OoT - Water Temple. Yes I know some people don't mind it, personally I find it terribily annoying.
- Super Mario World - Second world of the Special Level, don't remember the name. 

Killer is Dead, walking forever in your dream state for that one mission for the eater of dreams chick. So annoying.

Was gonna say the same thing! Worst Halo mission ever. 

I hate any sewer section you can name me.