I voted for the 612 race to Verbier. I did not like the Mustang one--they said they waited for years to find the perfect situation to have another big race, but the car was silly and the film was too long. I always thought they should have done the 2004 race again but with a new Vanquish.
London race, GT-R, 1949, and original DB9 were also quite good. I think Jeremy admitted that they got a little carried away with the Veyron one.