Fruiting Body is my favorite. That's one of their most aggressive, noisy old school industrial albums.
After that I'd go for Drowning in a Sea of Bliss, Viral Shedding, Befhlsnotstand, Tissue of Lies, and Duty Experiment. This is all late 70s/early 80s stuff.
I don't like their dance era that came immediately after that, e.g. Songs of Revolution.
A little later they are all over the place. Stoneface and Spiritflesh are good albums if you like minimalist, mystical ambient stuff. Nothing like the early 80s period.