One exception to that....Avro Arrow....there was never a prototype, first one off the line was to be an operational aircraft.

Unlike the YF-16 which was the prototype to the F-16 we know today, or the YF-17 which was the prototype to what we know today as the CF-18 Hornet, there was no prototype for the Avro Arrow. Granted they only build 6 aircraft before the program was scrapped (unjustly mind you, but that is a whole other ball of wax), they were all to be operational aircraft.