For me it has to be the Veilside 348 kmh run in new zealand...
This one is my favourite. When I was very young, my Grandad used to sometimes take me and my brother to 'The Great North Line', which ran through the field of a farmer he knew - it meant you could stand just a few meters away from trains at top speed. The sound of this Veilside approaching the camera is just like sound was of an Intercity 125 approaching at top speed 25 years ago, sends a shiver down my spine!