While Mother Teresa wasn't the only example of a Christian ministering to the poor, she certainly was a stellar example of someone who dedicated her life to serving those less fortunate than she. In doing so, she followed Jesus' commands and served as an example of what Jesus meant when he said, "If you do something to the least of these, you do it to me."
Mother Teresa was probably a good example of what Jesus taught with regard to ministering to the poor. But Jesus taught many different things with various examples, so one would not need to copy Mother Teresa in order to follow Jesus. Each person must find his or her own sense of inner direction and help the world in that way.
I don't think there was a nicer person on this planet earth, she was kind and giving on a scale that nobody has even touched. I think she puts the pope to shame and is what the religion should stand for in the long run. She was a angel on earth.
I do believe that Mother Teresa was the embodiment of Jesus' ideals with respect to ministering to the poor. More importantly, I think her work with the poor would have been seen as a very good thing by the historical Jesus. In my eyes, her actions were the type of thing Jesus was calling for during his time.
I'm a pretty firm anti-theist, and even i can't come up with anything bad to say about a woman who spent her life doing her best to minister to those who needed it. Truly a great lady, the religion would be far better off it contained many more like her,