The Cloud Product Monitoring and Validation page provides links for a variety of sensors

AVHRR - Advanced Very High Resolution Radiometer

VIIRS - Visible Infrared Imaging Radiometer Suite

MODIS - Moderate Resolution Imaging Spectroradiometer

PATMOS-x/AVHRR

NOAA-18 30-day running global averages
NOAA-19 30-day running global averages
NOAA-15 30-day running global averages
METOP-02 30-day running global averages

Timeseries Comparison (VIIRS/AVHRR/MODIS)

North Pacific
Brazil
United States

Collocated Scene Comparison (VIIRS/AVHRR/MODIS)

North Pacific
Brazil
United States