Inreasing the immmersion factor of Half-Life (Score 4, Insightful)

One of the most interesting aspects of the original Half-Life is that Gordon Freeman never spoke - all of the lines written by Laidlaw were generic enough that you could imagine yourself asking the question or making the comment which provoked the line. It drew you into the story even further by making you project your own dialog into it. It's strange that very few other games have tried this technique, as it seems to have worked very well.