I always liked a good drag race, but it doesn't really prove much for the practical power of a car. I've been in some cars that were not impressive at all coming off the line, just good, but they felt like a rocket taking off when accellerating at practical passing speeds, like passing a truck that's going 50 or 60 mph.
For car vs. car competition on the highway I've been a big fan of the 60mph roll-off, where you are both cruising at 60, then punch it.