Duke Nukem kind'o chatty an all. Something funny but nothing truly over the top but it does depend on the game, after all. I sometimes cant stand it when your main character says nowt. Half Life 2 being the main culprit,
"Gordon, go do this for me"
"I'll take that as a yes, now go do it.."
"Well, go on then..!"
It all seems too false to me. If your going to have a game that implies it's plot heavy you at least need your main man to say something otherwise it's not relatable in the slightest and glaringly disjointing as a whole.
I'd like a game that was akin to Peep Show. Your main character giving his own insight into situations as he sees them through a narrative, so to say, but you get a broad spectrum of replies to give.
That'd be fun.