You don't need to choose multiples, one will suffice but I'm going to list three. 

1. Bed of Chaos - Dark Souls Little needs to be said. Worst designed boss in a good game ever. You throw yourself at the screen praying you'll do what needs to be done without being sent to the void by spasmodic tree branches. And you'll do it because the game was good up until this point. Sadly the game goes down hill, it's already gone down hill and you just didn't notice. 

2. Folding screen monkies - Sekiro You can't even call it a battle, you chase monkies and kill them as all they can do is lightly cloak themselves but leave a trail of smoke to indicate exactly what route they took through the arena and they are quick little buggers. Frustrating, pointless and zero fun. 

3. Lady Osakabe - Nioh 2 A boss that requires a summons, some say it's very doable solo but I can't see it unless you use ranged attacks adn they're limited in the game so you'd need to really overlevel. You have two tentacles on either side of the arena that shoot ranged attacks, to fight one you have to turn your back to the other and there is no audio cues to help you out. No cue at all. This combined with the games dark realm phase mechanic where you get stripped of stanima regeneration make one of the most awkward, frustrating fight to take on solo. You better hope someone is online to help you through this or you're gonna feel intense pain. Quite possibly the most RNG luck based fight there is. 

Joker in Batman Arkham Asylum was god awful lol. Shame too because Arkham Asylum was Batman perfected with a great cast of boss fights……then you get to Joker as the final boss of the game. What a letdown.

Nintendo is very weak at boss battles. Everything else is always so great, but boss battles rarely hit. Mario Wonder is a prime example of this.

Bioshock Infinite is one of my favourite games, but the fight against Lady Comstock is annoying.

Xenoblade Chronicles 3 is excellent overall, but the final boss is a complete chore that drags on way too long.

Dusk is in my opinion one of the best FPS games ever made, but its bosses are meh.

Super Mario Bros. Wonder is one of the best games ever made but the Bowser Jr. fights leave a lot to be desired.
In Persona 5 Royal, the space boss (you'll know what I'm talking about) is BS.

Kudos to Legit for this thread. Luckily, I have never played any of those games, and based on the posts here, I have no desire to play any of them.

That being said, I would like to see Legit start a new thread on "Most Epic Boss Battles" in any game. (and I'm assuming you haven't yet done this)

For me that choice would be Atheon from D1. It is the boss at the end of the Vault of Glass raid. The VoG raid takes up to 6 people to complete, I died many times trying to beat him, finally got the job done in Dec. 2014.

Many great memories.

I might have made something similar though a most epic boss battles thread would just be people agreeing that Isshin Sword Saint is the most epic boss battle ever. That and the few insane people who don't agree. 

Can't argue with that, I've tried to come up with something from memory and nothing rings a bell to anything close to a great boss fight from Nintendo. 

As much as I love Spyro 1-3 the boss fights are mostly either pointlessly shallow or just bad.

Papu Papu in the first crash game also.

Bed of Chaos is god awful, great shout out.

I would add Aires in GoW. The final boss fight is super lame. Which is a shame because all the other boss fights are amazing.

I forgot the boss's name, but Elden Ring. The last boss is meh. Which is a shame because leading up to it the boss fights were excellent. The arena is too big and the boss is too fast and moves around too much.