As discussed by
aella_irene and
bedlamsbard Fiorenza Paolucci: Claudia Black in her Aeryn Sun period.
Cathal Paolucci: Richard Dean Anderson as Jack O'Neill
Helen: Scarlett Johannson
Richard: Jack Davenport
Victoria: Natalie Portman
Alambil: Helena Bonham-Carter (about six inches taller)
Eddard: Noah Huntley as Peter Pevensie
Cottia: Clare Danes (was Sienna Miller)
Piotr: Tom Felton
Susanna: Sophia Loren
Marcellus: David Wenham
Valentine: Sean Bean
Lucinde: Adrienne Palicki (was Clare Danes)
Tahmoh: Teresa Palmer
Iulius: Would have grown up into Richard Armitage
Cosetta: Gina Lollobrigida