Quite possibly <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />
Well... few games are able to create a convincing atmosphere or environment and in many game projects, the designers are the ones trying to do the writers' work. Most designers are rather technical folks and possess commendable skills in programming, 3d skin rendering and even technical quest designs but aren't that good at sharp wit, two-bladed retorts and even clever dialogue/narration .
And no, adding tons of dialogues and books is one thing but in DD, I truly felt like I was in some awesome gameworld.