It appears in this study that documentaries and reports are the favorite programmes of the French viewers (54% of respondents), before films and the news.
Even better, one in two French would like to see more documentaries about science (and even 57% of the 18-34 year-olds).

Synthesis report on:
http://www.scam.fr/tabid/363252/articleType/ArticleView/articleId/7438/Les-Francais-aiment-le-documentaire-.aspx