Yeah I definitely agree, one of the more interesting things about Oblivion to me is that different writers wrote all of the different guilds. The dark brotherhood is basically the only quest line in the game that gives you different choices of dialogue. Every other quest in the game has only one response, which looking back is pretty laughable as an RPG.

(Oblivion is one of my favorite nostalgia games and I listen to the soundtrack almost every day, it's just fun to point out interesting things in it)