All these data are temperature anomaly. Anomaly is the difference between temperature at a given time, and the average temperature for the same time of year during some reference period. So temperature anomaly doesn’t really tell you, in absolute terms, how hot or cold it is — it tells you how much hotter or colder it is, than it was (on average) during the reference period. And there’s the rub: these data sets use different reference periods. GISS uses the reference period 1951 to 1980, HadCRU used 1961 to 1990, and the satellite estimates use 1979 to 2000. The coldest of these reference periods is the 1951-1980 GISS reference, the warmest is the 1979-2000 satellite reference. That means that GISS anomaly is the difference between present temperature and a colder time period, satellite data are the difference between present temperature and a warmer time period.