Well i'm always amazed that in today's day and age so much of america still doesn't believe in evolution. But lets not go into that.
One of the major things that continues to convince me that it is true is that with every new discovery and new scientific method we develop we keep finding more and more evidence that supports it, and still haven;t found anything that disproves it.
Its a bit like a blurry image loading, we can see the overall picture from a distance, but each new development improves the clarity in a certain area.
Sometimes it doesn't turn out to be exactly what we were expecting and we have to readujst our viewpoint a little, but on the whole it all still fits together.
If anything was likely to blow evolution out of the water it was the recent advances in genetics. Suddenly we are able to look into the way things are acually made in so much more detail than we could before... and so this was a point where we could have looked in a new way and gone "oh heck, that doesn't do what i expected". But in actual fact the more we understand about the genetic makeup and connections of species the MORE it strengthens the case for evolution.
Its a bit "dumbed down", but the BBC programme Walking with beasts
(follow up to walking with dinosaurs) gives a really nice view of how the changes in the earth's climate, the habitat and the evolution of other species affects the evolution of tiny organisms into mamals.
The timescales are mind boggling, but seeing it all occur in "fast forward mode" does really help visualise the process. Otherwise it can simply be a bit hard to imagine.