Dickbugs episode. I know it's the cool thing or whatever to say you got through it no sweat, but during the recording I actually felt my gag reflex mildly engage once or twice. The adult baby episode was also gross.
Regarding NaNoWriMo, I much enjoy that episode, both recording and listening back to it, because I love shitty writing, especially shitty writing from people under the delusion that it's good writing. I think the secondhand embarrassment kicks in for me when I can tell that someone is genuinely unaware that they're being horrible and cringe-inducing, but for people who try too hard, like CodeCat and that guy in the cosplay episode who lied about scaring a guy outside of an Albertson's, they know exactly what they're doing, so they get no sympathy from me.