The reason I prefer voices, is because it adds emotion for me...
If they added in detailed parts of text like:
"*Her words are broken and they almost make it seem like she's about to cry as she looks at the sword you gave her from her dead friend, her usually strong demeanor fades and you are left with an awkward shadow of her once strong personality* T-thank you... I... I should b-... I should be going now."
As opposed to:" T-thank you... I... I should b-... I should be going now."
Then by all means, I'd love text. But the responses usually feel... fake.
That's the way I think of Voice Acting vs. No Voice Acting anyway. It's not like most of the characters in Oblivion held much emotion, either, but I think they did a better job in Fallout 3... :shrug:
So, in my case, it's more of an Emotional debate versus an Informational debate. I like connecting with the characters.
I'm not going to argue or state some random percentages, or hold my breath until I turn blue if people don't see things my way. That's all I'm saying, I like the emotions of the human voice.
Quick fix: emoticons!
I'm sure there could be a way to indicate emotion with text. You could have the NPC's facial features change to correspond to their emotion.
Granted, Silverfall svcked, but one interesting thing is that when dialog appeared, there was a little square picture of the character's face. I noticed that sometimes it changed depending on the mood of the situation for the given line of dialog.
Another method to add emotion would be to get more body animations. Again, I'm playing Tomb Raider: Legend, and I'm stunned at how many animations Lara's character model has (not combat/athletic related).
For instance, "*Her words are broken and they almost make it seem like she's about to cry as she looks at the sword you gave her from her dead friend, her usually strong demeanor fades and you are left with an awkward shadow of her once strong personality* T-thank you... I... I should b-... I should be going now."
Could be done where you physically see the transfer of the sword from your hand to her (shaking/trembling) outstretched hand. She could hold the sword and look at it, maybe even tear up a little, before the next string of dialog.
Comic books manage to convey plenty of emotion with pictures and words. It's a different medium, but just as powerful. Using text cues are often useful - bold and italics for shouting/emphasized words, for instance. Strong facial expressions also convey the tone/mood of the dialog.