Depends what I look: design, look, charater, dialogues, role in the actual game. I prefer her whole in CE, her TRON-ish design, she's serious, but she had some funny lines. However I think her best lines in H2! I just don't get it why her hair design changed in H2 and become cannon. Also many fan said her look is a bit oversexualized, especially for a ship AI. I don't feel that till Halo 4!