Bob and Margaret I will say right off the bat is not as slapstick as the Simpsons, Family Guy, or other such shows. It is not the type of cartoon you should watch if you are expecting gut busting laughter. But much like the two main characters, the series is meek but likable, and leave you feeling amused when it is over.
It is interesting to see a cartoon family with no children. Bob and Margaret are happily married and have little desire to ever have two children. As a result, there are different potential scenarios in the show than you find in a lot of other sitcoms and cartoons. A lot of the series humour comes from the nature of the two protagonists. Bob Fish is a dentist who is quietly smug and feels underappriciated, which can often lead him to taking steps that are down right foolish when he feels it is a chance to prove how much better he is than his fellow man. His wife Margaret is much more down to earth and humble. She is a kind, optomistic person who wants to help others, but often does not have enough faith in herself to carry through with anything. The two of them have very different outlooks on life, and yet their personalities complement each other in a way that makes their marriage seem believable rather than forced.
There are certainly some downsides to the series. The episodes can often end abruptly, making it seem like the dilemma was not truly resolved by the time the credits begin. The animation itself can be kind of shaky at times, so that while the characters are consistant, the series gives the impression that it is sort of second hand. However, the downside to this series can be easily overlooked, and I recommend people give the series a chance. It is not something that jumps out in one episode, but something that grows on you. The series' humour is subtle and understated, much like Bob and Margaret themselves.