I can't see any console which sold over 80 million units as a "loser", so PS3, Xbox360 and PSP are second or third place on the victory podium.
Especially when the second and third place both reached over 80% hardware sales compared to the first place and sold (each) even more software than the first place (PS3 + Xbox 360).
So my favorite losers are the Vita and the N64.