These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Bob's Burgers
Base Breaker: Gene, who people either love or hate. He often times tips over the edge of funny behavior and just starts getting annoying. This is something the show actually lampshaded in the first episode.
Linda tends to fluctuate between being unlikeably obnoxious and loveable.
Crazy Awesome: Louise. In "Ears-y Rider", an older kid steals her bunny ears and says he threw them in the trash. When Louise is told they've been incinerated, as revenge she calls in a favor to a biker gang and has them threaten to cut the kid's actual ears off.
The show itself, within the Animation Domination block. So much so, that it eventually got The Cleveland Show knocked off of the schedule!
Family-Unfriendly Aesop: The lesson in "Art Crawl" is, "some people are too fragile to be told the truth." Made even funnier by the fact that the episode seemed to be heading towards a more normal "always be honest" Aesop, but Bob and Linda couldn't go through with it after seeing that it would've caused Gale to have a Freak Out.
Growing the Beard: The writing really improved halfway through season 1 and never really slowed down. Arguably the second jump in quality was by seasons three and four, where the show focused on the kids and their bizarre adventures alongside the adults and the failing restaurant.
Moral Event Horizon: Millie Frock crosses this in the episode "Fort Night". In it, the children get trapped in their fort by a garbage truck and Millie opts to torture them instead of setting them free. However, that's not when she crosses it. She crosses it when Bob and Linda, worried to death over where their kids are, come this close to finding and rescuing them, only for Millie to lie to them and lead them away. Keep in mind that the children could have died trapped in there, which is hammered home when Daryl accidentally activates the truck's compactor, nearly crushing them alive.
In "World Wharf II" Felix leaves his brother and Bob tied under the pier so they'll drown when the tide comes in and he can get his brother's money. In the end he can't bring himself to go through with it and tries to save them, but when he confesses his plan to his girlfriend Fanny she puts the plan back on and attempts to murder Mr. Fischoeder and the Belchers.
Nightmare Fuel: In "Weekend at Mort's", Bob is nearly cremated alive trapped in a coffin by his kids.
"Fort Night" is chock full of this. It preys upon several adult fears by having the children completely trapped and at the mercy of a deranged child who won't let them go simply because they won't be her friend. Even worse is when they nearly get crushed to death by the compactor that's pinning them down.
"The Equestranauts" has a few moments, especially with the main antagonist's increasingly disturbing behaviour.
"Some day, you will all DIE, and I will have the body of a twenty-year old!"
The Scrappy: Hugo. There's no shortage of characters who make Bob's life a living hell, but Hugo comes off particularly unpleasant, as he usually gets no comeuppance for any of his cruelty. "My Fuzzy Valentine" in particular.
Justified: In the original pitch pilot to the network, Tina was supposed to be a boy named Daniel (looking exactly like his voice actor Dan Mintz. Not that much has been changed between Daniel and Tina, except that Tina is chubbier, shorter, and has breasts, whereas Daniel was skinny, tall, flat-chested, and had a bigger nose).
What an Idiot: From the Christmas Episode "God Rest Ye Merry Gentle-Mannequins". Really Bob, it's not a good idea to tell a mentally unbalanced man he's crazy or that he needs to "get over" his lost love when you're the one saying that he might kill everyone.
From "Fort Night"; Daryl betraying the group to Millie when they've finally discovered a way out of the fort they're trapped in. Placing your trust in a mentally disturbed child just so you can get Halloween candy just isn't smart.
Gene and Linda seem to pull a double whammy on this trope in "Christmas In A Car", Gene by running the cellphone's battery dry merely to request a song, and Linda for annoying the Candy Cane truck driver to the point of chasing them (as well as being the lynchpin for the events of the episode to begin with). Although the driver wasn't really dangerous in the end, imagine what would have happened if he was.
In "The Kids Rob A Train", all of the children wind up falling out of the 'Juice Caboose'. You'd think that just by reading this, this would fall under Adult Fear, right? The problem is that the episode notes at several points that the train moves very, very slowly, so much so, that you could walk alongside it easily (Louise even does so once she grabs the chocolate and hops off of the train). So, instead of running after the already slow-moving train, what do the kids do? They just stand there and watch and it moves away. Had Rudy not mentioned that the train does come back, the kids could have easily stranded themselves in the wilderness.
In "World Wharf II", Mr. Fischoeder doesn't treat being tied up to a pier with high tide approaching with any gravity whatsoever. Much less taunting his possibly mentally ill, gun-wielding brother while he and Bob are being tied up.
Bob: Oh my GOD, would you stop taunting your brother?!