Suggestions by @paulmantell

Alec Guinness

as Narrator (voice) in Robert Altman's Shrek (1981)

Score: +1

John Candy

as Dakimh the Enchanter in Howard the Duck 2: Hail to the Beak (1988)

Score: +1

William Atherton

as Thog: The Nether-Spawn in Howard the Duck 2: Hail to the Beak (1988)

Score: +1

Kari Lizer

as Winda Wester in Howard the Duck 2: Hail to the Beak (1988)

Score: +1

Fisher Stevens

as Paul Same in Howard the Duck 2: Hail to the Beak (1988)

Score: +1

Kevin Peter Hall

as Man-Thing in Howard the Duck 2: Hail to the Beak (1988)

Score: +1

Shannon Tweed

as She-Hulk in Howard the Duck 2: Hail to the Beak (1988)

Score: +1

Chip Zien

as Howard the Duck (voice) in Howard the Duck 2: Hail to the Beak (1988)

Score: +1

Ed Gale

as Howard the Duck (suit performer) in Howard the Duck 2: Hail to the Beak (1988)

Score: +1

Lea Thompson

as Beverly Switzler in Howard the Duck 2: Hail to the Beak (1988)

Score: +2

Don Marion Davis

as Sidney Falconetti in The Girl with the Gargoyle Tattoo

Score: +1

John Meehan

as Writer in Clueless (1940)

Score: +1

Busby Berkeley

as Director in Clueless (1940)

Score: +1

Jackson Beck

as Mr. Wendell in Clueless (1940)

Score: +1

Dorothy Dandridge

as Dionne Davenport in Clueless (1940)

Score: +2

Richard Carlson

as Travis in Clueless (1940)

Score: +1

Mickey Rooney

as Josh in Clueless (1940)

Score: +1

Lana Turner

as Cher Horowitz in Clueless (1940)

Score: +3

Christopher Lloyd

as R.L. Stine (character) in Goosebumps: The Movie (1998)

Score: +1

John Kassir

as Prince Khor-Ru in Goosebumps: The Movie (1998)

Score: +2