Classic Warner Brothers Heroes
I guess I better mention that these classic characters were demoralized in the ill-fated films of the later years such as Space Jam (1996) and Looney Tunes: Back in Action (2003).
Bugs Bunny is the sassy and shameless star of the WB lineup. He's not afraid to speak his mind and do what it takes to get what he wants, even (and especially) if that happens to be revenge for some wrongdoing to him. Unfettered by the strings that tied Mickey Mouse down as a corporate logo for squeaky-clean family-friendliness, WB was able to make Bugs Bunny as irreverent and classically comedic as they wanted, and they certainly did. Due in no small part to Mel Blanc's incredible vocals, and also because of the animation and direction of the studio, Bugs Bunny became one of the world's most recognizable characters. Bugs tackled the opera, fairy tales, Arabian Nights, celebrity outings, and scores of other interesting and varied situations. Decades later, Bugs and his friends became the inspiration for the animated series Tiny Toon Adventures.
Bugs Bunny's voice was originally provided by the inimitable Mel Blanc, although in later films, someone DID try to imitate him, and it was Billy West, whose voice you might recognize as Fry's from Futurama.
The perfect counterpart to Bugs Bunny's antics is Daffy Duck, the neurotic, self-important, high-strung duck with a particular personal issue against Bugs Bunny. Their rivalry fuels many of the shorts and films in the WB repertoire, and his attitude lends itself to many hilarious stories. His outer space alter-ego, Duck Dodgers of the 21st (and a half) Century is great, and brings us a lot of fun interaction with Marvin the Martian.
Daffy Duck's voice was also provided by Mel Blanc, while his voice in later years was provided by Dee Bradley Baker, who also provided the voice for David in some Lilo & Stitch spinoffs.