Suggestions by @user_340311

Lucas Till

as Jaime Lannister in The Tourney at Harrenhal

William Moseley

as Daemon Blackfyre in The Black Dragon and The Red

Ivan Kaye

as King Aegon IV Targaryen in The Blackfyre Rebellion

Lucas Till

as Jamie Lannister in Robert's Rebellion / The Storm King

Adam Driver

as Oswell Whent in Robert's Rebellion / The Storm King

Viggo Mortensen

as Gerold Hightower in Robert's Rebellion / The Storm King

Jonathan Rhys Meyers

as Arthur Dayne in Robert's Rebellion / The Storm King

Alexander Dreymon

as Benjen Stark in ASOIAF

Jack Black

as Patchface in ASOIAF

Katie McGrath

as Lyanna Stark in ASOIAF

Ruth Wilson

as Melisandre of Asshai in ASOIAF

Ben Barnes

as Benjen Stark in ASOIAF

Brad Dourif

as Walder Frey in ASOIAF

Clive Standen

as Sandor Clegane in ASOIAF

Taika Waititi

as Eddison Tollett in ASOIAF

Chris Hemsworth

as Daario Naharis in ASOIAF

Bryce Dallas Howard

as Lysa Arryn in ASOIAF

Richard Armitage

as Stannis Baratheon in ASOIAF

David Mazouz

as Jon Snow in ASOIAF

Charlie Hunnam

as Aegon I Targaryen in House of the Dragon