Smekermann
This is a really unique album in P.O.'s discography. The repetitive approach is similar to their other albums, but this is a much more atmospheric affair thanks to the band's experimentation with acoustics, and "loud silence" (ie. amps cranked to max) being used as drone to their rock.
Skyline is the outlier, in that it's a single riff played for 10 minutes straight. If you do manage to endure, you'll come out cleansed. Other live versions are more approachable, though (Circus).
Favorite track: August.