Swedish Death Metal you can play to your church-going 90 year old grandmother or at the very least you are comfortable knowing you don't have to reach for the volume controls every few minutes to avoid the growly bits.
Opeth sort of turned the corner quite a few years ago with the brilliant Damnation/Deliverance double album. One growly, one not. I'm not really a fan of metal, extreme or otherwise. This is something else completely.