I would have to say Kaede 100%.
Sure she may have freaked out on Asa but that's because Rin was all she lived for and she loved him, and at the time she felt that Asa was taking him away from her. That and the fact that Kaede had suppressed her feelings so much throughout the series just so Rin and the others could be happy.
Kaede and Rin go back way further than any of the other characters and they have such a dark and happy past together. In my eyes it should have been her. She deserved it more than any of them.