ECMWF vs NOAA forecast data accuracy
You can compare verification scores using this application from ECMWF made from guidelines by the WMO. The example below fits nicely with what is widely known, namely that IFS (the ECMFWF global model) scores generally best. In recent year the UK Met Office global model have also scored better than GFS. The figure shows the root mean square error of MSLP.
The example below of course only covers verification for one month, so you should examine longer periods and focus on the fields you are most interested in.