Every NPC has something unique to say in Guild Wars.

A little story or introduction about themselves. Each sidequest had individual dialogs inbetween the pickup quests, hand in quests and sell your loot ritual thats repeated over and over. Even the accept/decline windows all had something amusing in responce to the dialog.

It captured what I loved the most about RPG questing, the little short stories than captivate your imagination rather than just another drag 'n drop NPC offering your 7th kill quest.

It shows that the developers really care about the lore and background of the game, even if most of the population doesn't. Lucky for those individuals the gameplay in Guild Wars is extremely simple and you can just click through most of it to get to the "pwning"