I don't like Top Gear - although i find Clarkson midly entertaining - but james May just looks odd, and Richard Hammond looks like a ready-for-surgery transexual! How women find him attractive is a mystery to me!
Even if you are not a fan of Richard Hammond this was an interesting program.
Title was misleading as it was not about going to the centre of the earth but what the Earth is made up of, and why we have earthquakes, volcanos etc.
They had a huge "virtual earth" where they could look at the different layers that made up the earth, and all the tectonic plates and how they fit together and move around.