These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Family-Unfriendly Aesop: In one episode Ben learns that the morality of celebrities should not be a factor in whether or not we enjoy the art they produce. It wasn't why we became their fans in the first place.
"Funny Aneurysm" Moment: Any instance of Carol being teased about her weight. Hollywood Pudgy actress Tracey Gold, who played her, would go on to have a well-known (and near-fatal) battle with anorexia.
Almost any appearance of Boner, given the character's Unfortunate Nameand actor's tragic death.
A few early-season plots with Mike (him and Ben illegally betting on racehorses, throwing unsupervised parties) don't at all jibe with the adult, born-again Christian Kirk Cameron—or the Mike of the final season that was influenced by Cameron's newfound faith.
Retroactive Recognition: Matthew Perry, years before Friends, played Carol's doomed boyfriend, Sandy. Also, as mentioned above, Leonardo DiCaprio as temporary family member Luke. Brad Pitt and Hilary Swank also had small one-off roles.