[Sky Shark]

For me it would be the W driver, and the Sengoku and Genesis Driver for their sleek designs and relaying on their henshin devices the gia memories and lockseeds to make most of the sounds. That aspect I love as it just gives them so much leeway with what they can do and they aren't forced to get all the sounds set in stone by the time the driver ships. I still love their designs in the show because they're simple, intuitive and not cumbersome.