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.
Fridge Horror: Selma kicking Hans Moleman out of the car and driving off after their date. The car looks like the AMC Gremlin that Hans usually drives, meaning that Selma just stole Hans' car and got away with it.
Selma still accepting the pills for Lisa by the "doctor," even after he admitted he wasn't a doctor.
Hilarious in Hindsight: When Homer and the kids get ready to go to Duff Gardens (before Marge comes in with news about the funeral), he plans to get a discount on admission by telling the ticket taker that he's a college student (while the kids plan to tell the ticket taker that they're under six years old). A season later, Homer would actually be a college student in "Homer Goes to College".
One of the men in the 101 Frozen Pops magazine is Troy McClure. Season seven's "A Fish Called Selma" has Selma marrying and trying to have a baby with Troy McClure.
Nausea Fuel: Homer and the sandwich. It doesn't help that it's based on a true story that happened to one of the writers.