Free time activities allows young people to express their inner potential and develop a wide range of skills. It would be silly to consider a certain activity better than others, as far as everyone should follows its own inclinations. Nevertheless, If I had to suggest a young person a free time activity, I would tell it to read more books. It may appear a trivial activity, but I strongly believe in its value. 

Some people argued that novels have been exceeded by films and TV series, but it is definitely false. Films and series would not even exist without their script. I deeply love cinema and I used to be literally addicted to several series, but I think reading is the better way to stimulate our own imagination. On the other hand, screenplay writers and film directors have been deeply influenced by literary classics.

Many people consider reading as a passive activity and assert that reading is a waste of time. There is a bit of truth in their words, as well as our fancy is led by the author's creativity, but I strongly disagree on the wastefulness of reading. Umberto Eco said that people who do not read live just their own life, while reading is a way to live several lives. In other words, reading is one of the best way to employ our time. 

Nowadays reading books has become even more necessary. New medias expose us to a huge amount of information in a very short time. Scrolling a Facebook page we can read lots of news, but we are used to watch each of them for a few seconds. That has been proved to damage our concentration, while reading a book can help us to improve this skill.

In conclusion, reading is a thoroughly formative activity, which help us to better understand the world around us and even to imagine it  in a different way. 
Young people would not ever change the world if they could not imagine a different one!