Game of Thrones Playing Cards
Each of the four suits represent the four main Houses of Westeros:
Diamonds: House Lannister
Clubs: House Targeryen
Hearts: House Baratheon
Spades: House Stark
The characters represented in the number cards are somehow related to, significant to, or involved with the suit's main House and are ranked in order of significance (though on some occasions, I do admit to ranking based on popularity or what seemed to just make sense... i.e. all the Deuces).
Each number-card character has a portrait, name, and (associated) house sigil.