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? :
BrickLink - Set 7298-1 : LEGO Dino Air Tracker [Dino 2010] - BrickLink Reference Catalog
Dino Attack | Brickset: LEGO set guide and database
7477 T-1 Typhoon vs. T-Rex - Brickipedia, the LEGO Wiki
LEGO 7298 Dino Air Tracker | LEGO 7298 Dino Air Tracker Dino… | Flickr
REVIEW: 7477 T-1 Typhoon vs. T-Rex - LEGO Action and Adventure Themes - Eurobricks Forums
Dino Attack/ Dino 2010 - #19 by FordianL_at_the_BCC - LEGO - The TTV Message Boards
LEGO 7298 Dino Air Tracker | Lego, Brick loft, Dinos
Dino Attack Collection Complete ✓ : r/lego
Random set of the day: Dino Air Tracker | Brickset: LEGO set guide and database
LEGO Dino Attack: T-1 Typhoon vs. T-Rex (7477) for sale online | eBay