I think Liv Tyler has one of those faces you love or hate. My young male cousin claimed she looked like an alien and literally couldn't bear to watch her. For me she looked sulky a lot of the time though I have warmed to her in interviews. I thought Cate Blanchett waa perfect. She is a truly great actress and her slightly feline looks give her beauty an otherworldly quality. However to be fair I have never quite decided who I qould have preferred as Arwen.
But beauty is subjective. In objective categories there is no contest. Galadriel wins!