The Porridgey-Didge fiasco. What was supposed to happen: Amanda was sitting on a chair that would be incling until she fell into a vat of porridge. But she managed to hang on after Shaun managed to incline the chair all the way, so he decided to let her go... until Josh suddenly ran over and threatened to push her in. (He didn't).
The various guests delivering the Endgame envelope including Justin Bieber's carpet, a block of ice, Ziggy the world's tiniest zombie, Herbie the love bug, a zebra disguised as Scarlett Johannson, the inventor of Sudoku in a broken bumper car, and many others.
During the previously mentioned Time Warp version, Amanda as host becomes incredibly mean (which Josh finds incredibly amusing), especially to Shaun, which he protests.
Shaun (as Josh): I'm a lot nicer to you when I'm hosting.
Josh (as Charlie): It doesn't matter, because she's being mean to "me", which is you, and that's accurate. [...] She's being nicer to "me" than you usually are to me, which is you.
(Shaun reacts with confusion, head in hands)
Charlie (as Amanda, to Josh): Do you realise that this is the most complicated that this show had been, and you understand it?
In a playing of Guess The Guest, Patti Newton inhaled Sulfur Hexafluoride, causing her voice to become significantly deeper, much to everyone's amusement
Patti (responding to the question 'What do you do for a living?' ): I'm a mother (inhales gas, her voice deepens), a grandmother (inhales the gas again, her voice now in Evil Overlord territory) and a wife!