For me, Gandhi's greatness lies in the fact that his qualities can be admired at many different levels. The deeper you go, the more you find to admire. At the low end of the pool are the obvious things, like truth, non-violence, and the stewardship of the Indian freedom struggle. (Around here is also knowledge of all of Gandhi's faults.) But as you go deeper, you start appreciating his subtler qualities that don't get much airtime.