Jam/YMMV

Fetish Retardant - The eccentric doctor and his phone sex line.

My cock's just gone off like a spunky firework.

Hell Is That Noise - Several times.
- The farmers playing hideous instruments made out of piping and dead rats.
- "Today...we saw Richard Madeleyyy...beating up a cleaneeerrr...and later being apprehended...for fucking a coffee machiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiinnnnnnnnnnnnnneeeeeeeee..."
- The noise of a man screaming while jumping into a woodchipper is something you'd probably like to forget.
- The ambient, unnerving background music in most of the sketches, including the abovementioned woodchipper sketch, which incorporates a tense, somewhat catchy loop of the intro of Screen Kiss by Thomas Dolby. Particularly creepy combined with Mark Heap's unhinged monologue and the screaming, that sketch in particular has a way of staying in your head.
High Octane Nightmare Fuel - This troper was particularly horrified at the one where a man jumps into a wood chipper that sprays his bloody remains all over his ex's house (and into her face, as she was leaning out of the window).
- The man who wakes up and discovers he's just a head and a spinal column.
- The Gush.
- Most of it, really. The series, with few exceptions, is deliberately intended to make the viewer incredibly uncomfortable if not terrified. Unsurprising given that the opening more or less tells you it's about people who have totally broken down beyond all rationality.
- It has this effect on so many people that, according to The Other Wiki, Jam came 26th in Channel 4's top 100 scariest moments poll, beating actual horror works such as Carrie and Silence of the Lambs.