Free to Play (2014) [1] I've enjoyed this documentary a lot. It follow three DOTA players and theirs life prior to 'The International', a first million dollar e-sport tournament. What caught my attention the most, is that, despite the three main characters (Dendi - Ukraine, Fear - USA, hyhy - Singapore) come from very different backgrounds and cultures, they treat the game almost the same - as a way of living.

[1] https://www.youtube.com/watch?v=UjZYMI1zB9s