1. Oberyn Martell
While Oberyn might not have been the most favourable Game of Thrones character, his death was probably the most gruesome of them all.
In a battle against The Mountain – the giant that now protects Cersei Lannister – Oberyn’s cockiness led to him getting his skull crushed. By The Mountain’s hand.
Luckily, science has proven that such a death would be impossible as a human doesn’t possess enough strength – and our skulls are built to withstand such forces – but still, Game of Thrones isn’t concerned with science, and Oberyn’s death makes us wince just thinking about it.