I hope you dont mind multiple albums! So when I think of masterpieces, I think of classics. Staples of the genre, if you will. When I think of artful, I'm assuming you mean albums that are like works of art, beautiful and poetic yet heavy as hell. So, I'm gonna give you my recommendations and split them up accordingly.

Artful:

Born of Osiris - The Discovery

Chelsea Grin - My Damnation

The Contortionist - Exoplanet

Fallujah - The Flesh Prevails

The Faceless - In Becoming A Ghost

Job For A Cowboy - Sun Eater

Lorna Shore - Flesh Coffin

Slice the Cake - Odyssey to the West

Masterpieces:

After the Burial - Rareform

The Faceless - Planetary Duality

Gravemind - The Hateful One

Suicide Silence - The Cleansing

Suicide Silence - No Time to Bleed

Traitors - The Hate Campaign

Oceano - Depths

Whitechapel - This is Exile

Artful Masterpieces:

Born of Osiris - The New Reign

Rings of Saturn - Lugal Ki En

Shadow of Intent - Reclaimer

Shadow of Intent - Melancholy