Definitely quality over quantity. I have played too many games full of bugs that rapidly sap the enjoyment from free-roaming environments and eye-candy. My personal opinion is that I enjoy a good story that is well realised and immersive. I get easily tired of too many go fetch quests.
I recognise that it is challenging to have replayability, but there are lots of games that completing even one playthrough feels like enough. The gool old cprgs that everyone mentions have all of the features that make you want to replay them as different classes or races etc