I'm going to add the Dewoitine D.520, the Armée de l'Air is generally viewed as having been overwhelmed by the Luftwaffe in 1940 but the Dewoitine actually gave more than it took and its pilots liked it. It was quite modern in 1940 and, in a different scenario (if France and the UK had attacked immediately when Poland was invaded, rather than sitting on their heels, for example), might have really put some hurt on Germany's airforce.
Mind you, I don't know if it really fits in this thread: it has been forgotten rather than judged harshly.