Daffy Duck/Awesome

In "Ducking the Devil", Daffy attempts to recapture the escaped Tasmanian Devil for a $5,000 reward. Though in his usual "craven little coward" mode, he succeeds in luring Taz back into his cage via a weakness to music. As he counts his money, a single dollar bill falls to the ground and is swiped by Taz from under his cage door. To get it back, Daffy rushes into the cage and closes the door behind him. During the off-screen fight, Daffy is heard screaming, "LET GO OF THAT MONEY! IT'S MINE! MINE! DO YOU HEAR ME?! MINE! ALL MINE! AND WHAT'S MINE IS MINE AND NOBODY'S GONNA GET IT!" When Daffy exits the cage with the dollar, viewers see Taz dazed and beaten in the corner. Daffy then tells the viewer, "Like I said, I'm a coward, but I'm a greedy little coward."
Depends on how you feel about the movie, but Daffy going into full Duck Dodgers-mode to save the day in Looney Tunes: Back in Action was pretty cool.
"Porky's Duck Hunt", the cartoon that made Daffy a star.

"Don't let it worry ya, skipper, I'm just a crazy darn fool duck. WOO HOO! WOO HOO! WOO HOO!"
"It's me again!"

While the De Patie Freleng shorts rarely earn Awesome moments Mucho Locos may get special mention for Daffy malleting Speedy after hearing one too many tales about "El Stupid Duck". Notable for making Daffy one of the very few characters to actually win against Speedy in a short.
This obscure Tang bumper from The Bugs Bunny Show marks perhaps the only time Daffy has actually outsmarted Bugs.
Daffy's Rhapsody, for his first 3D outing, Daffy is quite the showman. Not only does he sing a song while Elmer Fudd chases him around the stage blasting at him without missing a beat, he comes out on top and gets applauded! Bonus points for bringing an old recording of Mel Blanc to the big screen.