Ocarina of Time. I never really finished games on the N64 and I had a lot, but I don't plan on finishing those since we no longer have them.
My "to complete list" goes like this: Ocarina of Time (GameCube), Majora's Mask (GameCube), Metroid Prime (GameCube), Eternal Darkness (GameCube), Legend of Mana (PS1), Final Fantasy 8 (PS1), Hexen (PS1), Blood Omen: Legacy of Kain (PS1), Sword of the Berserk (Dreamcast), Legacy of Kain: Soul Reaver (Dreamcast), Turok (Xbox 360), Thief: Deadly Shadows (Xbox), Peter Jackson's King Kong (Xbox 360), Batman: Arkham Asylum (Xbox 360).
My "to complete list" goes like this: Ocarina of Time (GameCube), Majora's Mask (GameCube), Metroid Prime (GameCube), Eternal Darkness (GameCube), Legend of Mana (PS1), Final Fantasy 8 (PS1), Hexen (PS1), Blood Omen: Legacy of Kain (PS1), Sword of the Berserk (Dreamcast), Legacy of Kain: Soul Reaver (Dreamcast), Turok (Xbox 360), Thief: Deadly Shadows (Xbox), Peter Jackson's King Kong (Xbox 360), Batman: Arkham Asylum (Xbox 360).