Secondly, it looks like the National institute for Media and the Family have given a favorable review of the video game industry. There is a pdf with an included buying guide - games to avoid and perhaps get.
I liked this one:
"Only 20% of kids who tried to buy M-rated games from retailers were successful."
Something parents have to deal with is not only the battle of saying no to an inappropriate game for their child but also dealing with an environment where the child's peers have somehow gotten their hands on the games in question.
The report makes some mention of addiction and cyberbullying among other aspects of gaming.