Inigo Sand

Kit Harington is playing Robert Catesby in the short series Gunpowder (which he also co-produced) - BBC (UK), worth watching and nearly as gory as GoT. Catesby, who led the 'Gunpowder Plot' to destroy Parliament and assassinate King James I, is one of Kit's distant ancestors.

Sibel Kekilli (Shae) is a detective in the German crime series Inspector Borowski. IMO she does a much better job in that role than as Shae, overshadowing the main character. Tom Wlaschiha also has a major role as an iffy police captain in one episode.

Iain Glen has a recurring role in an Australian series called 'Cleverman', and Kristofer Hivju has a major role as a detective in the Swedish series 'Beck'.

Faye Marsay (the Waif) is in a quirky-looking BBC series called 'Love, Nina', in the title role, a complete contrast to her GoT character. I only caught ten minutes of it but it looked as if she is a Northern (English) nanny to a London family in the literary world. She also played Anne Neville in a BBC series a few years ago called The White Queen, set in the Wars of the Roses period. She made a very convincing evolution from a playful and spirited young girl to the reluctant wife and widow of Edward of Lancaster, and then Richard III's mildly malevolent and finally bereaved and dying queen.

Charles Dance and Burn Gorman were recently in an Agatha Christie mystery, 'And Then There Were None'.

Maisie Williams was a recurrent (but evolving) character in Doctor Who, joined by Donald Sumpter in the finale Owen Teale appeared as a police chief in 'River' (BBC) and Rose Leslie will be a main character in 'Luther' (also BBC).

Not sure if this has been posted already - Maisie Williams is in an Irish comedy film, 'Gold', complete with Irish accent: https://www.youtube.com/watch?v=q2CtPlgu3xo