I might have a few if the standard for "best" is held low. I have a couple more I really like but this is probably enough.
1. UP3985 moving 60 mph in Holden, MO. Far as I know I'm the only one to photo UP steamers moving at night.
2. UP844 undergoing bearing replacement in Kansas City, MO
4. Victoria Island, BC (Alberni Pacific RR), fireman adding sand to clean flues. Not easy to take a photo in a moving cab!
Kent in SD