I disagree. The requirements can have little to do with the quality. The end user has no idea of the requirements but they sure as hell know about quality.
A product that executes its intended purpose correctly for the majority of its expected life at an apropriate accepted cost. Again based on the end user...
A quality product, is one that has an over-design safety factor of 2.0 built in it, has to work out of the box, and has no failure for the life of the warranty.
Donald Source
I think a quality product is "A product which satisfies customers' needs with regards to functionality, reliability, safety and cost effectiveness"
Milind Source
For a truly interesting read that approaches "quality" from a more philosophical direction and a great addendum to the left brain answers. "Zen and the Art of Motorcycle Maintenance: An Inquiry into Values" by Robert Pirsig
Don Source