Doug's Doug Funnie and The Ren & Stimpy Show's Ren and Stimpy
Disney's House of Mouse's Minnie Mouse and The Simpsons' Martin Prince
Voiced by: Russi Taylor.
Fun facts: Taylor has voiced Minnie Mouse since 1988 (she is only the fourth person to do so). She has also provided the voice of such memorable characters like Gonzo on Muppet Babies, and Webby Vanderquack, Huey Duck, Dewey Duck, and Louie Duck on DuckTales, as well providing the voices of Üter, Sherri, and Terri on The Simpsons.
Tiny Toon Adventures' Buster Bunny and Aaahh!!! Real Monsters' Ickis
Voiced by: Charlie Adler (although he only voiced Buster Bunny for the show's first two seasons).
Fun facts: Adler, who began his voice-over career in 1984, has also voiced characters on '80s classics Jem and G.I. Joe, as Eric Raymond and Low-Light, respectively, as well as providing additional voices for characters on '90s cartoons such as Captain Planet and the Planeteers, Rocko's Modern Life, Eek! the Cat, and Darkwing Duck.
The Simpsons' Bart Simpson and Kim Possible's Rufus
Muppet Babies' Animal and Bobby's World's Bobby
Goof Troop's Pete and Darkwing Duck's Drake Mallard/ Darkwing Duck
Voiced by: Jim Cummings.
Fun fact: Cummings also voiced characters on five other Disney Afternoon shows: DuckTales, Chip 'n Dale Rescue Rangers, Quack Pack, TaleSpin, and Bonkers.
Rocko's Modern Life's Heffer Wolfe and SpongeBob SquarePants' SpongeBob
Futurama's Bender and Kim Possible's Dr. Drakken
Chip 'n Dale Rescue Rangers' Gadget Hackwrench and The Simpsons' Agnes Skinner
Voiced by: Tress MacNeille.
Fun facts: Along with Agnes, MacNeille also does the voices of Simpsons recurring characters Cookie Kwan, Brandine Spuckler, Dolph, Lindsey Naegle, Bernice Hibbert, and the Crazy Cat Lady.
SpongeBob SquarePants' Mr. Krabs and Superman: The Animated Series' Lex Luther
The Smurfs' Papa Smurf and Scooby-Doo, Where Are You!'s Scooby-Doo
Rugrats' Tommy Pickles and The Powerpuff Girls' Buttercup
The Real Ghostbusters' Egon Spengler and Animaniacs' the Brain
Animaniacs' Pinky and Teenage Mutant Ninja Turtles' Raphael
Darkwing Duck's Megavolt / Elmo Sputterspark and The Simpsons' Homer Simpson
Voiced by: Dan Castellaneta.
Fun facts: Castellaneta might be synonymously known as the voice of Homer Simpson, but, in reality, he has actually had a rather extensive voice-over career. He has voiced characters such as Arnold's Grandpa Phil on Hey Arnold!, Earthworm Jim on Earthworm Jim, and the Genie in Aladdin (the TV series).
Scooby-Doo, Where Are You!'s Fred Jones and Transformers' Megatron
Voiced by: Frank Welker.
Fun fact: Welker was the original voice for the character of Fred and, since 1969, has continued to play him in almost every animated adaptation and reboot of the series.
The Flintstones' Barney Rubble and Heathcliff & the Catillac Cats' Heathcliff
Voiced by: Mel Blanc.
Fun fact: Known as "The Man of 1,000 Voices," Blanc was literally the voice of almost every single classic cartoon character, including Daffy Duck, Woody Woodpecker, Porky Pig, Tweety Bird, Sylvester the Cat, Yosemite Sam, and of course, Bugs Bunny, whom he continued to voice up until his death in 1989.