I have seen very few episodes, but my favorite one would have to be the one when they drive the supercars in Paris. Favorite line from the episode:
"All the POWER is just AMAZING!" - Jeremy Clarkson, driving the Ford GT.
Also, Hammond talks about the Zonda's power to weight ratio. Camera cuts to Clarkson:
"I bet you any money Hamster is sitting in that silly orange Zonda now, banging on about power to weight ratios. The fact of the matter is that car has the aerodynamic properties of Elton John and no spectacles. So its top speed is only 202. This does 212 and that's... more."