Here are my votes for the "Best Lines" said by a Ducktales character:
Launchpad: "what a beautiful sunset! You have to get up pretty early in the morning to find a better one!"
Gizmoduck: "Nobody can stop Gizmoduck from doing...whatever it is I'm doing"
Bubba: "Bubba Clubba!"
Mr. McDuck: "I earned my fortune by being smarter than the smartees and tougher than the toughees." He said that several times. Mostly because it was true.