Which famous family is posing for this lovely portrait?

It's The Skarsgårds!

From left to right:

Alexander (36): source of the most epic breakup playlist of all time
Sam (31): a doctor (did you miss the memo or something bro?)
Gustaf (32): Floki in History Channels' Vikings
Eija (21): a club promoter in Stockholm
Valter (17): some small parts in Swedish television shows
Bill (22): Roman Godfrey in Netflix's Hemlock Grove
And then the two youngest sons from Stellan's marriage to his second wife.