In the episode featuring Dimples, Jon Taffer and his experts watched as a cook was cooking a medium burger without flipping it for almost fifteen minutes, ensuring it was both burned and unevenly cooked. Near the end, they were yelling, "Flip the burger!"
In the episode featuring Piratz Tavern, the head "chef" Jucianno attempts to show his "signature dish" to the chef Taffer brings in, having never tasted it himself. The dish is just chicken strips with enough red-hot pepper spices on it to qualify as chemical weapons. The chef is nearly overwhelmed just by getting a scent of it, and when does he take a bite, he instantly spit it out. The chef then tells Jucianno to try it, at which point he almost immediately wheels around and spits it out into a trash bin.
In the episode featuring Chilleen's, a horse walked into a bar. Yes, someone rode a live horse into the bar, right in front of Taffer.
During the Zanzbar episode (and that is not a typo; the sign contains that misspelling), one of the first things that happens to the poor undercover patrons is that a guy who has been way over-served sits next to them and tries to talk to them. What comes out is complete gibberish. What does it mean? God only knows.
Drunk Guy leans back like he just imparted great worldly wisdom. Mystery Diner turns away with a "what the hell was that" look aimed right the camera.
James' antics throughout the Cashmere episode, which included walking in the women's restroom, ripping off his shirt while DJing, sitting on the bar top itself and pretty much acting like a tool to everyone he interacts with. All while saying "All in!".
The Whip noise effect that plays every time he says it just makes it funnier.
During Critters and Quitters, Taffer and his experts are watching one of the spies trying to chew poorly made mozzarella sticks. Taffer actually times her to see if she'll get to sixty seconds before spitting it out. To the spy's credit, she does.
The raccoon plopping down from the ceiling into the bar and running out the door. During service. Just like the horse from Chilleen's, he finds the time to leave a little present behind.
The "chef" from Fairways Golf and Grill provided plenty of schadenfreude as he struggled, and failed, to prepare even the most basic food properly, and failed to demonstrate any knowledge of how to run a kitchen. What made it funny was that he continued to lie about his qualifications, even as it became obvious that he couldn't even make a burger properly.
It's particularly easy to enjoy his suffering because he's an emotionally-stunted Man Child who took advantage of his friend, the owner, to get a job he couldn't be fired from.
However, towards the end of the episode, he starts looking more like a Jerkass Woobie, after he's fired and his sous-chef is promoted to his former position. Not only has he been psychologically broken from being proven as an incompetent liar, but his best friend has (understandably) turned against him and he's unemployed. The Stinger tells us that, six weeks after the rescue, the owner is still getting calls from the chef, looking to get his job back.