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.
Ear Worm: Many Neil Innes songs ("Star of the Sexy Movies" and "Say Sorry Again" contending for the worst cases), but most of all, the intro tune. Doo doo dum dum...doo doo dum dum. Doo...doo...dum... ...DAH DAH DAH DAH
Hilarious in Hindsight: The (dull and borderline incompetent) house band in the "Old Gay Whistle Test" sketch is named Toad The Wet Sprocket. Idle re-used it in the "Rock Notes" sketch on Monty Python's Contractual Obligation Album, and the real Toad The Wet Sprocket borrowed the name from there.
Even better — Eric Idle originally created the name 'Toad The Wet Sprocket' with the intent that it'd be so ridiculous, no band would ever take it.
The "Ill Health Food Store" sketch mentions that on the menu is an opportunity to take home a vegetarian and force-feed him meat. Sounds like Deadpool◊ is a regular customer...
Nightmare Fuel: The Pommymovie within a show segment is rather disturbing. Also, the Ricochet Brothers (and one sister), despite how funny they are — it's their identical suits, their identical speech. The fact that they seem to be Gang Of Bullies to their one sister doesn't help, either.
True Art Is Incomprehensible: Pommy — He'll Tear Your Ears Apart, a spot-on parody of the 1975 movie adaptation of Tommy and director Ken Russell's output in general.