34. Stannis and Selyse Baratheon
Stannis and Selyse have a loveless marriage, and sacrifice their daughter Shireen to the Lord of Light, at Melisandre’s behest.
33. Sansa Stark and Joffrey Baratheon
Before Joffrey brings Sansa to see her father’s severed head on a pike, and threatens to shoot her with his crossbow, there was talk of the two marrying one day.
32. Lord Petyr “Littlefinger” Baelish and Lysa Arryn
Lysa reveals in season four that she poisoned her husband Jon Arryn, and wrote a letter to her sister Catelyn blaming it on the Lannisters, to prove her love for Littlefinger.
Lysa’s past actions led the Starks to the South, and to the untimely demise of Ned Stark. Lysa and Littlefinger are essentially responsible for all of the events that help catalyze the War of the Five Kings.
Littlefinger manipulates Lysa for his own political gain, and ultimately ends up killing her by pushing her out of her own moon door.
31. Melisandre and Stannis Baratheon
The high priestess Melisandre acts as a guide and spiritual advisor to Stannis.
Melisandre seduces Stannis, and has him impregnate her with a magic shadow that assassinates Renly Baratheon.
The relationship between Melisandre and Stannis is more goal-oriented than romantic. After Stannis dies in battle, Melisandre realizes she bet on the wrong horse, and moves on to offer her advice to Daenerys Targaryen.