Anyway here's my list:
The Battle of Bikini Bottom: Horrible abomination that is so disgusting that I can't even look at the screen for the majority of the episode. Without a doubt the episode with the animation that bothers me the most. I know I shouldn't be bothered by it so heavily but I am. And also, the whole clean vs dirty battle idea was stupid and the episode was annoying. Sand Castles in the Sand was so much better than this.
The Motion Picture: Most people seem to find it to be amazing, but I just find it meh. It was annoying and had a lot of bad gross-out, and I hated the part where Patrick had blocked the camera with the circle thing. There were some jokes in here that I liked (to be more specific, the part where Mermaid Man messed up his lines, "did somebody say boom?", The beginning moment with the villain's car being towed, and Mermaid Man falling asleep before the movie started were thr jokes I liked), but most of them were annoying or gross. I personally don't get the hype for it
Patrick Smartpants: Mixed episode to me, I liked how we could symphatize with Patrick here and it was a little emotional, but Patrick was also rude and annoying here, and this episode has easily one (two, actually) of the worst sounds I've ever heard in anything. Even The Loud House hasn't had a sound as bad as this one. It's so bad I have to mute it when that sound comes.
The Curse of Bikini Bottom: I find this episode to be really bad, the atmosphere and tone of the episode felt kinda creepy and depressing in a not-good way and it made it uncomfortable to watch, it wasn't funny at all, it was boring, and Spongebob and Patrick got punished really hard here when they didn't do anything wrong. And the only thing good about it was the visuals.
Buried in Time: Extremely boring and forgettable, espicially the Plankton part. It was pretty funny but everything else was a bunch of either meh or pretty bad
Karate Star: Extremely boring and forgettable and a little annoying, I didn't mind Patrick in it that much but I have trouble thinking of too much that I liked about it outside of the idea of Patrick playing karate.
Extreme Spots: Yet again, EXTREMELY boring and forgettable, except this time it's much worse in that than the 2 above were. And this one was annoying too.
Shuffleboarding: Absymal episode, Spongebob and Patrick were extremely annoying and aggravating here, the episode wasn't funny except for one joke, it's really stupid, and Mermaid Man and Barnacle Boy are treated way too badly here.
To Squarepants or not to Squarepants: The only thing I liked here was the beginning where it acted like someing insane was going to happen, only to say that Spongebob was changing his pants, and then the women screams. Everything else had horrible charatization with almost every character, extremely frustrating and annoying, boring and forgettable, unfunny, and this had a stupid episode premise. Spongebob LongPants was much better at doing this
The Gift of Gum: Very disgusting and boring, and I disliked the big gum ball. I liked when Spongebob tried to "steal" it and there were people living inside the gum ball, and when the guy yelled at his tires, that's honestly about all I liked though. At least it's much better than The Amazing World of Gumball, although that's not saying much.
Waiting: I feel like nobody ever mentions it but I find it severly annoying and Spongebob ****** me off here.
Mermaid Man vs. Spongebob: After the first minute it wasn't funny at all and it was boring and forgettable, yet again. I feel like somethig really cool could have come from this idea but instead we just got a bunch of boredom.
Le Big Switch: Extremely annoying, stereotypical, and boring. Maybe even a little mean-spirited
Slide Whistle Stooges: It's the same joke over and over again. That's it
Porous Pockets: Extremely boring and annoying, and Spongebob was terrible here. At the very least it isn't like the similar Loud House episode.
Grooming Gary: The first 8 minutes were terrible, just a bunch of Gary abuse and all the other pets suffered the same treatment, and it was very boring and annoying. It got better once it got to the pet riot though.
Trenchbillies: Extremely annoying, boring, steroeotypical, gross, and frustrating, with an absymal ending.
Free Samples: People call it one of the best episode of Season 8 and I don't see it at all, extremely boring and possibly the most forgettable episode of the series. Perfectly average. I can barely even remember what happens in it.
The Other Patty: Extremely boring, just a worse version of Best Frenemies, and Spongebob trying to force Mr Krabs and Plankton o be friends really annoyed me.
Move it or Lose it: Extremely boring and Meh, it's just a bunch of nothing. I find it strange that people compare it to episodes like Glove World RIP
The Googly Artiste: Kinda similar to the three above this, except that this one is actually bad. The episode is extremely annoying, boring, unfair to Squidward, stupid, etc
Sportz: I feel like people have been softening up to this episode, I still think it sucks. Extremely annoying and even aggravating, bad charatization, humor is pretty all the same stupid slapstick over and over again, bad plot, and could have been executed so much better. In fact, I have a theory that this episode (and The Incredible Shrinking Sponge) were made entirely for advertising purposes
Squid Baby: Not actually underhated but I hate it so much that I wanted to mention it regardless :P