Marvel’s Jessica Jones: The Upstairs Neighbors

Robyn and Ruben staring out from a partially opened door

Fraternal twins Robyn and Ruben live together in a New York City apartment building, sometimes baking banana bread but mostly arguing loudly.
From the Netflix series Marvel’s Jessica Jones

Game of Thrones: The Ironborn

Yara Greyjoy and Theon Greyjoy glaring to one side

Yara Greyjoy (Asha Greyjoy in the books) and her little brother Theon
From the television series, Game of Thrones, adapted from George R. R. Martin’s A Song of Ice and Fire novels

Firefly: Idiot Child and Mei-Mei

Simon and River look on

Dr. Simon Tam gave up everything–his medical career, his fortune, and his reputation–to protect his younger sister, River, a psychic and genius in everything she does, who was experimented on by the government because of her incredible abilities.
From the TV series Firefly

Game of Thrones: Children of the Rose

Margaery and Loras Tyrell sitting and waiting

Scions of House Tyrell: Ser Loras and Margaery.
From the television series, Game of Thrones, adapted from George R. R. Martin’s A Song of Ice and Fire novels.

Dexter: Duo in the Dark

Debra and Dexter Morgan

Dexter Morgan: Blood spatter analyst for the police by day and serial killer by night.
Debra Morgan: Law enforcement officer unaware of her older brother’s murderous activities.
From the Showtime series Dexter

Image from Showtime

Children of Dune: Children of Destiny

Leto II and Ghanima Atreides standing

Leto II and Ghanima Atreides, the twin children of Paul Muad’Dib, the messianic former ruler of the known universe.
From the Sci-Fi Channel miniseries Children of Dune adapted from Frank Herbert’s Dune books.

Carnivàle: Faithful Siblings

Iris and Justin Crowe shown in middle-age and as children

Iris Crowe and Brother* Justin Crowe have looked after one another all of their lives.
From the HBO series Carnivàle

*Younger brother is a Methodist minister.