What is the most accurate driving directions site?

Hi, I'm planning to drive to San Antonio Texas and have never driven over that area. I was looking at Yahoo Maps, Google Maps and even Rand Mcnally Maps, they all give different directions, some even say left or wirte or vice versa on the same steps? Which one has proved to be more reliable, or which do you use?|||Google Maps|||Google Maps, or you could just buy an Atlas.