What is quality? Is it measurable? Is it subjective?

There are always new movies rolling out. What makes one quality and another not worth recommending? I live in Utah in an area where there's a total of 120housesin my ward. We like to have "block parties" to keep us in touch with the neighbors. What is it that makes the party from March a "quality" party, but the one in September not so good? How are you measuring quality? What are your evaluation methods?