I mean S1 you can actually see that hikigaya's romcom is going wrong, meanwhile S2 to S3 is basically your casual riaju romcom nothing wrong with it. S2 and S3 is just your typical riajuu having hard time choosing his best girl while enjoying push and pull harem life.
My conclusion if you enjoy the comedy and having casual watch sticks with S1, if you're looking for an outcast to riiaju transformation just go ahead to S3, S1 is almost completely irrelevant, you can even skip S2 if you want doesn't change much of your watching experiences
