I can't sing at all and I have to say there is much pathos in these songs, but for some reason they are excellent for rehearsing the pronounciation - when I'm alone! Maybe because they are not fast songs. I really like how the french words roll on my tongue. I have not really explored French music.
Funny, I had not heard about Ensiferum at all! It sounds pretty nice.
The others you mentioned are a bit too much metal for me.