There, Reddit user Mst3Kgf mused to the good folks of r/movies, "There's two things in Home Alone that unfailingly make me laugh every time, and neither of them are the obvious choices like Culkin or the trap-related slapstick..."
"...One is the nonsensical rage noises Joe Pesci makes in lieu of swearing. Pesci is, of course, one of the patron saints of cinematic cursing, so him being limited due to the confines of a family-friendly film is hilarious. You can see he so badly wants to drop F-bombs like he does in Scorsese films, but instead, he sounds like Yosemite Sam throwing a fit. It just adds to the frustration and rage for his character that he can't just lose it like he usually does.
The other is the conversation between Catherine O'Hara and John Candy in the polka van. I was not surprised at all to learn that was completely improvised by those two, as it must have been like old times for the friends/SCTV costars. The funeral story alone would be funny, but Candy's matter-of-fact, almost cheerful way of telling it, plus O'Hara's reaction, make it arguably the funniest scene in the movie."