I am going to be completely frank with you, and I have to admit, finally to myself also. My 17 year old has been playing games for years. I didn't condone it, but my husband did. One of those, "I never had anything growing up, so my son will get some of the things I couldn't have" situations.
I have found over the years that my sons moods actually change sometimes when he is playing certain games. Now, you need to know that I am NOT of the mind that video games will make my child do devious acts or that they are evil. But, I have no problem standing up to anyone that they do affect your children.
For instance, the Mature games. Your child is shooting people and blood is splattering out of them. I know, you will never let your child play those kinds of games. And good for you if he never does. But after like 10 years of playing, that is what the games in our house have led to. My son would start getting mad if he was getting beat, actually seriously mad. I would then tell him to shut it down. If a game you are playing "for fun", makes you feel like that, it's time to put it away.
The graphics these days are amazing. And along with that goes the reality of what is actually going on. One of the games actually has drugs and prostitution on it. For pete's sake! I do monitor what he plays and if I am with him I tell him No for certain games. He knows I mean it and doesn't argue. But he also knows that next month Dad will probably let him rent it.
I know I kind of got off track here. I guess my bottom line is: get fun games that actually throw some education in. yes, set a time limit. I think an hour a day is quite enough. Especially in the warmer weather. If we get snowed in, I might let it go a little longer. I will be honest and say my son plays longer than that. But, he does have a 4.0 and is doing fine in school.
Make your rules and stick to them. But remember, keep an eye on those games. They really have gone way too far on some of them and the morals are just not there at all.
R.