After just recently being introduced to Insomnium, I now regard them as being one of, if not the best melo death metal group ever.
There are a few similarities to Opeth (a few of the acoustic break downs sound very similar to Opeth's work) yet the songs seem more "complete".
Insomnium - Disengagement
Youtube compression naturally wrecks the sound. Go and grab a copy of "Since The Day It All Came Down" for the full effect.