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.
Dude, Not Funny!: Enfield and Whitehouse have said they deeply regret the decision to incorporate references to the real life breakdown of Tony Blackburn's marriage into the Smashie and Nicey sketches, essentially pulling this trope on themselves.
Kevin the Teenager to levels where he got his own movie.
Seinfeld Is Unfunny: Wayne and Waynetta Slob were supposed to be over-the-top caricatures of every negative stereotype of poor council-estate dwellers but since the word 'chav' entered the national consciousness and everyone started doing it, they seem unoriginal and not particularly funny.
Sequel Displacement: In a sense. Kevin The Teenager is really a sequel to the "Little Brother" series of sketches but, while anybody in the UK who watched comedy shows in the nineties will be able to quote Kevin and even imitate his mannerisms, very few of them will know that he evolved from the Little Brother character. (Unless, of course, they saw the sketch where the transformation occurred: at the exact moment he turned 13.)