I personally recommand Those french metal bands who deserve to be listened:
Dagoba because they are a good carbon copy of old Fear Factory.
Gojira too. (The singer is gonna be working with Max & Igor Cavalera in a new band) recommanded album: "From mars to sirius"
As a french, I have a lot of difficulties to listen this type of music with french lyrics. It's often ridiculous or boring (as it is also the case in English but fortunately I don't understand 80% of the lyrics....)
The only french band with french interesting lyrics I recommand is
Lofofora, even if it is often very politically oriented.
recommended albums: "Le fond & la forme" "Dur comme fer" and "Les choses qui nous dérangent"
Noir désir is also a good rock band, but not a metal band. (But the singer is a big asshole murderer)