Don't know about a list, but most Michelin Road maps mention the highest point of a mountain pass.
Quite sure a lot of the higher ones are to be found in the Alps. So search around on the maps of the countries around the Alps and that will help you into the good direction.
Actually I think Michelin does a map of the Alps.
I know the 'Grand St. Bernard' highpass is among the highest ones. I been up it riding in the night with moonlight, crazy experience. Especially because we camped on the top.
BUT... since the highest mountain is not in the Alps you could conclued that the highest road also isn't. The highest European mountain is actually situated in Oeral (Russia). I think it is the 'Ebro' but I am not sure. Also, the road might go higher, but changes are it will not be paved...
Guess it depends on what you consider to be Europe...