very fast ...
If I do remember correctly, the fastest one was the beautiful CV-990.
Actually the speed record for a transatlantic flight of a commercial passenger airliner should be still held by a Swissair aircraft between JFK and ZRH at near or even just above (!) M1 with the help of a terrific jetstream! I will google the web to find out more info, but any one is welcomed into the search, might be some former SR crews can help.