Suggestions by @carolbangle

Carlos Alazraqui

as Rocko in Rocko's Modern Life (1980's)

Score: +2

Tom Kenny

as Heffer in Rocko's Modern Life (1980's)

Score: +1

Tom Holland

as Dog in CatDog

Score: -3

Will Arnett

as Cat in CatDog

Score: -3

Tara Strong

as Courtney in Total DramaRama

Score: -1

Tara Strong

as Courtney in Total DramaRama

Score: 0

Carolyn Lawrence

as Dot Warner in Animaniacs

Score: +2

Jim Cummings

as Wakko Warner in Animaniacs

Score: +1

Carlos Alazraqui

as Noi in Minecraft: Story Mode - Season 3

Score: +2

Jim Cummings

as Ein in Minecraft: Story Mode - Season 3

Score: +1

Ryan Reynolds

as Squidward Tentacles in Elite Cinematic Universe

Score: +1

Shia LaBeouf

as Rocko Rama in Elite Cinematic Universe

Score: +1

John Mulaney

as Rocko in Nicktoons the movie

Score: +1

John Mulaney

as Rocko in Cartoon Network V Nicktoons

Score: +1

Taylor Swift

as Avatar Aang in The Nicktoons Movie

Score: 0

Taylor Swift

as Timmy Bagge in Courage The Cowardly Dog Cinematic Universe

Score: 0

John Leguizamo

as Detective Jake Neo in Courage The Cowardly Dog Cinematic Universe

Score: +1

Andy Samberg

as Harold Bagge in Courage The Cowardly Dog Cinematic Universe

Score: +1

Tom Kenny

as Spongebob Squarepants in Nickelodeon Meet the Characters

Score: +1