Ok, let's start with the most internationally well-known of the French punk stars: Métal Urbain (first 7inch of Rough Trade, that's cult, kids!).
Heavy distorted guitars playing mathematical riff on primitives beatbox rhythms. First electro-punk band ever. Nothing less than that. And according to the legend, they gave the aim to Steve Albini to create Big Black, and Jello Biafra is a huge fan. Cult, kids, I told you.
Ok, Steve Albini is a joke (and the baddest producer ever) and Jello Biafra quite an idiot.
Honestly, the problem is Metal Urbain had for singers something sounding like a drunk dog barking stupid lyrics (OK, non French speaker doesn't have this problem, still the barking is quite... hem.... embarrassing). Criticising a punk band by the barking of the singer is quite lousy, but, honestly it's the main problem of Metal Urbain (with the beatbox sounding out of rhythm and the quite common and unimaginative riffs). So commonly they were flirting with the really bad and the worst.
Still a few total cool songs such as Panik, Paris Maquis, Hysterie Connective, E 202 and Crève Salope (that one's got quite funky lyrics like 'Die bitch! You got blood in your cunt! You stink, you shit, you scream! A chainsaw in your face! You blow up, red all around!' Yeah, they certainly can pretend to be the first grindcore band ever)
The really funny thing about them is that they are actually widely respected in France as a French Sex Pistols and are actually seen as Situationist legatee. They're actually just bad and singing non-sense pseudo-anarchist shit.
After a while, Metal Urbain split to form two other bands, both underrated when you compare it to what they did before. On one side, half of the band (something like 2 guys) went to form Metal Boys, and the rest (something like 2 guys) went form Dr Mix And The Remix.
Yeah both names are shit. I don't know that much about Metal Boys, I heard 2 songs maybe. It's sounding a bit like a Japanese Telex (like a homemade Yellow Magic Orchestra, if you prefer). Well at least in my memory.
I do think Dr Mix And The Remix is better. The project was to cover some legendary R'n'R songs in an electro-punk style. Honestly, that sounds far better than anything by Metal Urbain. Imagine the J&MC guitar noise with the Big Black beatbox and some mechanic Lou Reed vocoder voice, in some Chrome noisescape... Really goooood. And fucking violent. The pre-industrial/noisy robotic rock cover of Sister Ray is an incredible blast. (here is just a 30 sec-clip, just put in a loop 22 times and you will have something sounding like the actual song)
After that, Metal Urbain decided to reform some years ago (well 2 guys with some professional) and finally committed an absolutely terrifying shit, produced by Jello in person. Don't buy, don't even download it, it just sucks. And it's not even funny. (Ok, the title is funny: J'irais chier dans ton vomi, roughly "I will shit in your vomit")