A counter-argument to the "The Simpsons is better than Cheers" argument, endorsed by Alan Jacobs here: The Simpsons is broader, though if broadness is the criterion, Friends has to beat out The Simpsons: it's on the air more, the better seasons are on the air more, and you're more likely to make a Friends reference that the average college student will get than one from The Simpsons' glory years.
But, that aside: Cheers is better because it's better: better written, better acted, better plotted than The Simpsons. It tried to do more, and succeeded in doing more. Its superiority is also evident in the quality of its writing, which is at all moments excellent, even when the plots themselves are kind of dull. One can follow the script of a Cheers episode and learn a lot about how to write television comedy; The Simpsons teaches nothing similar, and is in fact wildly misleading when one tries to figure out why it's humorous. To see this, look no further than shows which obviously take each as inspiration: the quality of shows inspired in one way or another by the Simpsons is uniformly low, sometimes embarrassingly so. The (much smaller) number of shows that take Cheers as an inspiration are considerably better. We don't judge a teacher by their students, but when the most prominent students are Family Guy and Parks and Recreation, it might be worth considering that the difference is not accidental.