I believe that the largest piece of evidence for evolution has yet to be discussed. The fact that when we are growing in our mother's womb we start off as the first organisms started off, and in the nine months we spend in there we basically go through our evolution on a smaller scale. We start off as a single cell which eventually replicates.
Did you know that at one point we have structures which appear to be gills? Did you know that throughout much of the pregnancy, the human fetus has a tail which eventually will shorten and dissapear (and that some infants are actually born with a small part of this tail which did not revert back into the body, in cases such as these it is easily removed via surgery) And that throughout the beginning of the pregnancy we have webbed hands and feet.
The changes we undergo in the mother closely match the proposed pathway we have taken in evolving over the past billion or so years.