Nine Inch Nails, Broken, although not purely metal (metal/industrial crossover), has some damn fine production.
My personal favourite is Oracle Moon by Garden of Shadows. Whoever produced that album understood the concept of overhead and gain staging, because one can really hear deeply into the mix.
I've been listening to Underworld's Dubnobasswithmyheadman Super Deluxe Edition on and off all day. This was such a departure from their previous albums when it came out, that it still stands out as my favourite, by a long shot.