*sigh*The Easter eggs only work on Xbox. I don't know about the way to change it on PC. However if I *were* to start playing around with that stuff, might I suggest changing it to "GameCompleted=2", not 3. The Easter Eggs will only work on your THIRD playthrough (not your fourth, not your fifth). When I got them on the Xbox, it was during my third playthrough, and my third one alone. When I started a 4th game (even though I hadn't even finished my third one), all the dialogue went back to normal.
And yes, in order to see that scene with Atton, you have to be female (male for Handmaiden, for obvious reasons, as she never joins your party if you're female).
Seriously, though... really not worth THAT much hassle, IMO.
THAT being said, and back on topic... My favourite lines have got to be (other than anything Atton ever says regarding the female Exile's appearance, clothes, or lack thereof):
Atton Rand: Anybody here catch that? All I understood was 'very'.
Bao-Dur: I think he wanted us to give up the General to his poorly-trained collection of bounty hunters.
Atton Rand: Ah. Well, that would explain it. Which one do you want?
Bao-Dur: I'll take the stupid one who decided to threaten us rather than shoot us when he had the chance.
And there's always:
Exile: [Force Persuade] Give me all your credits and jump into the central pit.