Might be in the minority here but personally I think the Best helicopter LEGO ever made was the Dino Attack T-1 Typhoon. What do you consider the best one they made? :
T-1 Typhoon vs. T-Rex : Set 7477-1 | BrickLink
LEGO MOC Helicopter from LEGO CREATOR 31058 alternative build instruction on youtube | Lego creator, Lego, Lego challenge