The fact that Amy's Baking Company managed to be so unhinged that a single episode has its own subsection on the series' main page. It takes a lot to stand out amongst 12 seasons worth of shows produced in two different countries.
The quote on the top of the main page comes from the American episode "Sebastian's", where the owner was a complete egomaniacal nutcase who pretty much tried to actively sabotage Ramsay's efforts to improve his restaurant, hurting not just the business but the staff as well. After Sebastian tries to push his "concept" one final time, Ramsay pulls him aside and calmly tells him that. After watching this guy act like a massive Jerk Ass the whole episode, seeing Ramsay put that schmuck in his place is immensely satisfying.
In that same episode, Sebastian is crowing that "I just won that one!" after Ramsay walks out on an argument to clear his head. Upon returning, Ramsay announces, "You have won jack fucking shit!"
In the Spin-A-Yarn Steakhouse episode the owner, Saki, has his wife serve the restaurant's new signature prime rib table-side as part of an effort to involve her more in the business. Being new to the task she cuts enormous portions, practically giving away the meat. After an entire sports team arrive and all unanimously chose to order the steak, the owner, wife and Ramsay find out that (to their horror) there was only about 2 pounds of Rib left, certainly not enough to serve an entire team. Cue Victor, the head chef (who earlier in the episode was reduced to washing dishes during dinner service because of the lack of help) mentioning that he prepared one last Rib roast just in case something went wrong.
It's not made entirely clear to the viewer just why this is so crucial. Prime rib is different than some other steaks because it takes much longer to prepare properly. First, it (i) sits at room temperature for about two hours, then (ii) spends another two hours in the oven at varying temperatures. Without the "emergency" prime rib, then it would have been literally impossible to fill the order and no amount of chef wizardry could have done anything about it.
In the Park's Edge episode, one of the line cooks has voiced opposition to including chicken wings on the new menu, and begins to intentionally screw up orders during the relaunch night. The head chef, who had no previous experience outside of cooking school, tells him to stop complaining and just cook the food properly. When the line cook mouths off again, the head chef fires him on the spot in the middle of dinner service.
In the Black Berry's episode, the owner/head chef walks off the line in the middle of the relaunch after being called out for interfering with the other chefs and reverting to her old ways, which included meddling in dishes that others were cooking. The sous chef, with some encouragement from Gordon, steps up and gets every dish served properly once she leaves.
Another in that episode is basically anytime that Mama Mary opens her mouth: First, she tells her daughter to shut up, ditch her arrogance, and accept the help that Gordon is offering, and the second is when she confronts her daughter for walking out of the dinner service, telling her that if she is going to behave like this, she should just close the restaurant down. Not to mention her red velvet cake was the only food Ramsay liked during his sample meal.
Gordon catching and confronting the guy who's stealing food and booze from the kitchen (named, appropriately enough, Buzzard) and getting him fired is at once badass, awesome, and quite brave too. Gordon instantly bursts the guy's bubble as soon as he comes swaggering into the kitchen wearing a pair of Cool Shades and then tells him what he would do in the situation:
Can I see your eyes, can you take your glasses off?
I just have one discipline, anyone who steals from me is out. End of story.
Gordon's utter shredding of the owners of "Burger Kitchen", who insisted upon almost force-feeding him their gimmicky Wagyu burgers, to the point of getting in the way of David's, their (former) head chef, attempt at showing Ramsey his own burger recipe that the owners were refusing to implement.
Ramsay bringing in all the people who wrote the bad reviews on the restaurant was also epic, showing how yes they're real people, not trolls or spokesmen for the competition.
Gordon's "The Reason You Suck" Speech towards Amy and Samy and their business, Amy's Baking Company. They simply refuse to listen to him and repeatedly try to play the victim card, he just outright tells them he can't help them and leaves.
Ramsay during that entire episode was awesome, calling the owners out multiple times on their bullshit and twice telling customers what was wrong with the place. He also stuck up for the abused waitresses, telling the customers that they were getting their rightfully deserved tips stolen. Given the managers' behavior, he acted very calm and mature and was a much bigger person than they were. Any other person would have given up on them a long time ago.
This exchange between Gordon and Joe, owner/chef of the Mill Street Bistro.
Gordon: Defensive, ignorant, and in complete denial...
Joe: Guess what, if I'm all that, you're my twin.
Gordon: I can cook, Joe.
That whole episode was amazing. When Joe decides to put Raw onions in a French Onion Soup and Ramsay goes off on him with such anger and ferocity.
In the Piccolo Teatro episode of the UK series, Gordon decides to prove that lunch services can be profitable by opening the restaurant for lunch without the owner's knowledge. He ends up prepping, cooking and serving the lunch item (tomato soup with a toasted cheese sandwich) by himself, and ends up making over €500 in profit.
The Mamma Cherie's episode started off with a rare moment of awesome for the restaurant. For probably the only time in the show's run, Gordon Ramsay liked the food and didn't send it back. He thought the presentation wasn't the best and the restaurant was a little small, but he cleaned his plate.
In the Lido di Manhattan episode, half of the kitchen staff walk out on Gordon and the owner of the restaurant. Gordon quickly saves things by calling in his right hand man Scott and with Scott's help, they save the service and make it a success.