Well, the Cleveland Show is just a spinoff of Family Guy.
So is American Dad, as it's been shown the two shows are kind of like parallel dimensions. xD
Seriously, take a look at Family Guy, American Dad, and The Cleveland Show.
They're all about An Idiot(Peter, Stan, Cleveland) with wife(Louis, Francine, Cleveland's wife) who's too good for him, a son who's an idiot (Chris, Steve, Cleveland Junior), a Daughter everyone hates. (Meg, Hayley, Roberta) and a straight-man/pet. (Stewie/Brian, Roger, Rilo)
...It's strictly formula.