As far as I can remember, there was not a single living individual I respected more than I did Madiba. That would explain the fact of my weeping on the morning I heard of his death, which is something I never did for any single individual. For some time now, I actually asked myself which of his many deeds lead to such reverence, and I don't really know. I do strongly suspect though that it's the key role he played in ending government-sanctioned racism against non-Caucasians in South Africa. Being a Black citizen of that country, this is something that affected me personally, and something I will eternally be grateful for. In addition to that, this man is also not just a hero (being a freedom fighter), but also a saint (promoting reconciliation with the oppressors). It's not only that, but also the fact that he is constantly hailed as an icon of peace.
For a number of times, I would ask myself if there was anyone alive who garners greater respect, and the only person who came close is the current Dalai Lama, but I must admit I don't know much about him, beyond his winning a Nobel Peace Prize. Another candidate is Desmond Tutu, who frequently speaks against injustice, and also happens to be a winner of that most prestigious of awards.
There is one other candidate, Noam Chomsky, whose intellect and activism I deeply respect. Watching and listening to some of his political work some time in 2012 led me to consider him the most valuable person alive. His influence is likely smaller than that of the above-mentioned candidates, but being the world's foremost Anarchist is quite something, especially given that it's the most attractive of all political theories I've yet encountered.
So, with a disclaimer that I am largely ignorant of world events, Noam Chomsky takes the place of Nelson Mandela as the living individual I admire the most.