DH8D:
maximum (takeoff/go around) 1020, as has been mentioned; climb power 900, cruise power 850 (also useable for climb and landing; brings some reduction in noise and performance).
DH8C: Maximum 1200, intermediate setting 1050, cruise 900 rpm. Also on this series, 900rpm is allowed for climb and landing with some performance penalty but noticeably less cabin noise.
NK-12 powered turboprops (Tupolev 95, An-22): 700rpm, which results in supersonic tip speeds due to the large propellers. Still seems to be efficient though.