Light Yagami
This shinigami was featured in the director's cut OVA, "Death Note Re-Light: Visions of a God". Like Ryuk, he is bored with the shinigami realm, and convinces Ryuk to tell him the story of Light Yagami and the Death Note. Inspired by the tale, he heads off for the human world, in search of a similar cure for his own boredom.