Naturally, the Stark direwolf sigil is a popular choice:
"[No Spoilers] Game of Thrones tattoo that I got earlier this year, Fresh vs Healed. from gameofthrones"
"[NO SPOILERS] Got this beauty the other day and wanted to share from gameofthrones"
That includes Sansa Stark herself:
"[No Spoilers] Sophie Turner’s tattoo!! from gameofthrones"