https://en.filae.com/v4/genealogie/h...epageconnected
Of course, many French BMD records and censuses are available for free on the local sites, but this one (a pay site) is particularly useful if you don't know the precise location of where your ancestor or relative lived. It also has some records which you wouldn't find on the local council sites, such as family trees.
I used this site a long time ago to view a census entry - they let me view one image free of charge, if I remember correctly - but I never managed to find it again. Nice to know that now they have an English language version of their site.