Video games can not be good for teens. They make their lives much harder than they need to be. Video games teach them bad things. They also keep them from doing more important things. They're addictive, and if I were a parent I wouldn't let my kids have more than one video game system, and they wouldn't be allowed to play it a lot.
Video games encourage violence and bad language. When teens see people and monsters on video game fighting, shooting, and hurting each other, they think that it's cool. Teens are very impressionable, so this makes them want to be just like the characters. So they go places and get into fights, and copy the bad things that the characters say to each other.
Video games also can become antisocial and isolated from other things if they play video games. My brother play video games on his computer and game systems all the time. The other day, when we went to a few stores, he said he wouldn't ever go shopping with us again. He just wanted to get home and play his video game! Other people play video games a lot more than he does, but that doesn't mean he should play them so much.
The games and game systems teens use cost a lot of money! My brother saves his money most of the time, so he'll have about $100 and then when he sees a video game he wants, he just blows all his money on it. With game systems, teens will buy one, and spend a lot of money. That's fine. But then a newer one will come out, and they want that too. Then another, and another, and so on. They spend all their money on things that aren't important!
Video games make teens skip out on important life skills, like communicating with friends in person. They skip chores, to play some dumb video game. Video games sometimes keep them from doing homework. They get bad grades, and maybe even fail out of school! Teens shouldn't be allowed to play video games for more than about an hour per day. Would you want your teenager to get bad grades? Would you want them to become antisocial, bad-mannered, and violent? Nobody should!