I think that the best leisure activity for teenagers is playing sports. Firstly, they can find friends who have the same interests. Secondly, physical activities are a good way to relieve stress and reduce depression. Moreover, sports can help develop teamwork and leadership skills that may be very necessary for their future jobs. Their parents should give advice on choosing a suitable leisure activity; however, teenagers themselves will make the final decision.  

My opinion, parents should decide for teenagers spend their free time sensibly. right balance between learning and playing. First, young people can play thirty minutes in their free time after school is finished. during work breaks, teens can play sports such as basketball, football, badminton and so on. have few friends, free time is not known, then on facebook all day. it's a waste of time. Second, young people can read books to develop the brain and thinking ability. Third, young people can help their parents with housework in your spare time, or go charity with her parents. Fourth, parents should provide for youth participation in social activities so that they are more confident and make friends. for this reason, parents should let teens participate in activities or play in their free time and do not create pressure for teens.

I believe the best leisure activity for teenagers is any group activity.
In my opinion, the parents could watch the way their children use free time. The parent should give some advice on what leisure activities are good for their children and how to mange their space time effectively. If the teenagers have time-consuming activities or they are addicted to bad hobbies, then the parents need to talk to them and show them how to take up useful leisure activities.
This could be playing a team sport or joining a hobby group or even volunteering. Firstly, teenagers like to feel that thev belong to the group. Secondly, being part of a group helps teenagers make friends. Friendship is very important to teenagers. In addition, they will make friends with people who have the same interests as them. For these reasons, I think group activities are best for teenagers.