My son will turn 5 in February. He probably plays video games/computer games about 3 hours a day. Then tv another 2 hours a day. I know, bad. He gets up in the morning and plays Band Hero (drums or guitar)while we are getting breakfast and ready for the day. We are usually out of the house until 2pm (kids either have preschool, bible study, or playtime at the park, etc.). Then from 2-3pm is Quiet Time/Naptime for both kids. If my son stayed in his room for the whole hour and played quietly (so his 2 yo sister could take her nap), I will let him play games on PBSkids.com for about an hour or so every couple of days. On the other days I try to give him something else to do or find something to do with him (reading, preK workbooks, board games). The TV is usually on at our house from 5pm to bedtime. We eat dinner in front of the tv. DH comes home around 630pm. Kids go to bed between 7 and 8pm. A couple times a week my son and hubby will play a game online together for about an hour.
I agree that the length of time my son is playing games is too much from what other say. But I honestly feel that he gets a good balance of everything. He is a physically active kids, outgoing, compassionate, does good in school academically (he can already read short books), loves sports of all sorts, loves music (hence the Band Hero), loves going to church and bible study, and loves being outdoors.
I think it also depends on the kid. For my son this schedule works, for others it wouldn't. My daughter has no interest in video games and only watches Noggin shows on TV. She prefers to pretend play with her dolls or ride her scooter (she will turn 3 in April). Already at that same age my son was into computers, music, video games, and sports.
Also, the computer video games are considered a priviledge in our home that needs to be earned. So if my son is being disrespectful or not abiding by our rules at home, gets into trouble at school, etc. This is the first thing that gets taken away. Lying is an immediate offense (my son lied to me yesterday about taking a piece of candy from the counter...video game time last night was taken away). If he has behaved during the day either at school or at home with me and he has abided by the Quiet Time rules, he will get to play for an hour or so in the afternoon.