A Red Letter Day, from Half-Life 2.
Because you basically follow Alyx into a room, you walk around and fiddle with bits, people exposit a LOT (which goes counter to the AMAZING intro where there WAS no exposition) and it's mostly useless shit (essentially: 'here's backstory, now go to Eli who will tell you why you're here'), then there's a contrived reason for you to go through the excessively-boring Canals.
Being locked in a room so people can talk at you but not tell you anything worth knowing? Bullshit level design, right there.
Lots of bad level shit in that game, though. The final level is awful because it presents no challenge--it's like suddenly playing a game with a gun that's been modded with 999 dmg. Ravenholm, while GREAT from an audiovisual standpoint, showcases the game's reduced ammo count, forcing players to rely on the game's physics (Half-Life 2 is pretty much just a contrived physics tech demo, anyways). Sandtraps was a bunch of needless physics stuff, with really fucked up pacing (Half-Life 2 is basically 'bad pacing, da gaem').
I could pick on a game like Legendary or something, but, hey, why not a 'great' game? Don't get me wrong; there are good levels, which I genuinely enjoy, like Ravenholm (yeah, I know what I said above), Nova Prospekt, Anticitizen One (I think?), and Highway 17, but the game's first few hours, and occasional bits throughout really, really irk me.
Also, I may sound nuts, but you know when I stopped liking Nova Prospekt? When Alyx showed up. In fact, as I look back on the game, I realize that I don't like a single bit where I'm hanging with her.
Wow, I love that level. Sure you don't just hate it 'cause it's a Flood level?
The first time through, I got kinda confused by it, but ever since then, I've had a blast going through it with multiple loadout types (just like every Flood level other than Keyes, which is awful because of the infinite Flood and too-narrow corridors), just trying to see what I can do. The only part of the level I actually hate is the corridor section with the ranged Flood forms, because it really sucks on Legendary, and kinda on Heroic. The hiddenish flamethrower seems pointless.
Uh, could be Two Betrayals, Assault on the Control Room, The Library, or 343 Guilty Spark.
Personally, I think The Library is amazing. It's the level that weeds out people who don't know how to play first person shooters. I could wax eloquent on this, but I'm tired. The basic idea is that FPSes are easy to pick up and play, but because of that ease, they're kind of hard to come to grips with. There's not so much a skill curve as there are two distinct skill levels--one for everyone, and one for people with really good spatial skills. The Library is the level that really forces you out of your comfort zone. Halo has an insanely wide variety of ways to play, not just with the sandboxy levels, but the massive enemy gamut and the weapon sandbox. Unfortunately, players seem to get fairly comfortable playing just one way--they tend to find Halo boring as a result, and hate The Library because of this. It's a game that forces you out of your comfort zone. You go from popping out of cover and picking guys off to suddenly being forced forward, nonstop. If you're stuck playing one specific playstyle, then, well, the Library will fucking destroy you. It's a work of genius, and only bad players hate it.
Two Betrayals and Assault on the Control Room are the same level, in reverse. I used to hate 'em, because they were repetitive, but when I returned to Halo, after years of playing video games and actually becoming somewhat good at them, I discovered that, holy shit, they're actually pretty fucking awesome. They're a series of nigh-identical arenas with varying setups of enemies and weapons. Here, Halo is trying to encourage the player to try different things. It's like "hey, hey, hey, you there, try new things!" So it presents you with a lot of superficially similar situations, then remixes them. So first, you go through it with increasing difficulty (iirc, the last room before the gauntlet up the tower to the control room proper) until this room with some hunters, and then you're sent back through, but this time, in increasing difficulty with Flood. It comes directly after The Library, IIRC, which is a 'pure' Flood level.
Basically, Halo's structure is like: covenant + getting used to driving --> covenant but more focused (and hunters, hi) --> ultimate covenant sandbox that is SILENT CARTOGRAPHER (I love this level) --> 'now let's have fun with covenant' --> meet the flood and phase out covenant --> pure flood level --> reintroducing flood + covenant --> full-on flood + covenant (fuck Keyes, though, seriously) --> now put it all together and you have The Maw.
The levels are repetitive in part because the game wants you to feel comfortable with navigating spaces so you only have to think about combating the AI, rather than being enamored with the level spacing. So it's all about encounters with enemies and changing that up across playthroughs, rather than having a lot of unique corridors.
Then there's 343 Guilty Spark, which I tend to get lost in. I enjoy playing it, but it's hard to navigate--easily the hardest to navigate level in the entire series.
Halo is basically a mirrored game. I mean, your journey is bookended on the Pillar of Autumn, Assault on the Control Room/Two Betrayals is a thing, and then there's Truth & Reconciliation/Keyes. But, given how complex Halo's AI and weapons are, I'm pretty sure I'd be insanely satisfied just playing a randomly-generated selection of enemies and weapons inside a cube.