I would class Raison d'être more as dark ambient, not darkwave. Dark ambient mostly features little to no drums, while darkwave usually features "normal" amounts of drums and is generally faster and more active in terms of movement.
Older Depeche Mode, for example, is what darkwave mostly refers to (the most famous example).
http://en.wikipedia.org/wiki/Dark_Wave
If you intended to mean dark ambient, then I can recommend these albums:
Delerium - Morpheus
Mark Morgan - Fallout OST
Ulver - Svidd Neger
Atrium Carceri - Seishinbyouin
Desiderii Marginis - Deadbeat
Letum - Broken
Predella Avant - Carbon Figures
Raison d'être - Within the Depths of Silence and Phormations
Raison d'être - In Sadness, Silence and Solitude
Raison d'être - The Empty Hollow Unfolds
Sephiroth - Cathedron
And a couple of albums somewhere between Dark Ambient and Darkwave:
Coph Nia - Shape Shifter
Sephiroth - Draconian Poetry
Ice Ages - Strike the Ground
Ice Ages - This Killing Emptiness
Ulver - Perdition City
The Protagonist - Songs of Experience
Karl Sanders - Saurian Meditation
Dark Ages - A Chronicle of the Plague