one of the first, maybe THE first, to use a spinner.... giving it that 'shark' look.
I'm not very original here... going with probably the favorite for most.. The Sopwith Camel, although I wasn't that fond of UK's paint scheme on it, during wartime that is... I've seen some restorations that have magnificent paint schemes.
Frankly, I don't think there exists a bi-plane I do not like.
I don't have a 'favorite' plane, I have many.
BUT... if you twisted my arm and made me pick I think I'd go with the Ford Tri-Motor. And it's not just the exterior it's also the cockpit AND the passenger compartment. I can't think of any more elegant plane that ever flew. - JamesJM