Careful going too far down this road.
The caustic version: Video game writing is crap. It's terrible. Why do they use the spoken word at all? Wouldn't it be better if developers just forgot they ever took creative writing as a middle school elective and stick to making pretty things that explode when you shoot them?
The long version:
The last two games I've played were Portal then Resident Evil 4. That's a big come-down. It's left a bad taste in my mouth.
Most writing is crap, just by volume. But you filter. When you filter out all the crap writing in the world you're left with a ton of books, a lot of theatre, a good bit of movies, some television, and only about a half-dozen video games.
But I love video games. And a large part of that is that writing is not the point. The fact that Bowser kidnapped the princess is not really there to provide motivation. It's just there for explanation. It's just something to drop into: you must perform this set of ridiculous tasks so that <<SOMETHING HERE>>. But if you're going to spend a lot of time on the story itself, it should be pretty good. If your game's mission is to rescue the "president's daughter," understand that it's glaringly obvious that the mission is crap, and don't spend a lot of time building it up. Certainly don't mention the phrase "president's daughter" twelve times during one conversation. The phrase isn't magical. It's just <<SOMETHING HERE>>. The story from the original Doom was one page printed and terrible. But it was a great game. Resident Evil 4 has terrible terrible dialogue that makes you wish you hadn't heard it. It really ruins the fun for me. When the main character said, "I have a bad feeling about this." it took away from the game as a whole. Not because it's a cliche spoken by a paper cut-out character, but because he had already been attacked by pitch-fork wielding zombies. "The 'bad feeling' you have 'about this' is liquid dookie dribbling down your pant-leg!"
Games excel when they realize that the developer should spend a ton of effort on the writing, but the player shouldn't. You can play Portal with the sound off. There's nothing in Glados' dialogue that you really need to win, and you're almost never stopped so you can hear it. It's freaking GREAT, and you miss a lot if you don't hear it, but it never gets in your way.
Here's an exception to that: I enjoyed the living crap out of Deus Ex. I think it was a great game, and well written. But it didn't make you spend too much time on dialogue trees because it knew that as much work went into the game, it still didn't have the writing caliber of ... say ... the television show Alias which isn't exactly Shakespeare either.
Look at free little games like
Passage. It packs a punch artistically, and the only symbolic language of any kind is your 'score' in the top right. Youth, love, success, lonliness, aging, death, and sudden loss are all told in five minutes with no words.
So I says, if your game has a story, make it unbelieva-brilliant, and then never let it get in the player's way. Make sure they're experiencing the story, and not reading/listening to it as much as possible.