I think the funniest content in the game is found in build/buy. My favorite is the Cornucopia Toybox from Supernatural:
The Cornucopia Toybox and Life Lesson Generator is the perfect companion for your children! It will teach them the value of boring, repetitive tasks, like putting small things in a box. It will teach them that everything fun eventually comes to an end. It will remind them that each time they add a new toy to their expanding play narrative, they are increasing the size of the mess they will soon be responsible for. Buy a Cornucopia for your children, and you're practically done being a parent!
I've barely scratched the surface and I don't have all the packs, so I would love to see some other choice descriptions.