>>211876745 (OP)Diane herself wasn't necessarily the problem, but the show wasn't very funny until after she left. Most episodes had like 1 decent joke and many times I didn't even laugh at all in an episode. Sam and Diane have almost zero chemistry, it seems entirely forced by Diane (and at one point Sam I guess). Sam and Rebecca have much more natural chemistry, which is kind of ironic, since the premise is Sam forcing it because he can't stand that there's someone who's not into him.
Coach was pretty much the only funny character in early seasons but once you get to the Rebecca seasons everyone is decently funny. Still not as funny as shows that came after it though. It's comfy, at least. But even in terms of comfy sitcoms there are shows that are consistently funnier.