Qays Wii Sports Resort is probably the best videogame that's been released in a decade or so.
"Quality" can be defined in different ways because there are different kinds of quality.
If you want to buy a car you can either get a big and fast one or a small one that needs less fuel and is save. Both are quality cars.
If you are looking for a game you can play together with your friends (which, to me, is a very important sign of quality) Wii Sports Resort beats almost every other game on the market.
And I'll tell you something: When Wii Party is released I'll buy it instantly and play it with my friends for months and months, just like millions of other people. And you still won't understand why it'll be a quality game.
Oh and Twilight is a quality book (apparently. I haven't read it) because people usually read books to experience the adventures of the main characters. Apparently, Twilight is exactly what a lot of people, especially women, want to read. So yes, it is a quality book. It just doesn't offer the kind of quality that you want.