It just HAS to be 43175 from a low angle on a three-quarter, front facing profile at Carmarthen in 2004 (if memory serves correctly...!) en-route from Swansea to Pembroke Dock on the morning run. Cloudy day and everything, but the shot is absolutely superb. Never beaten it yet, might never beat it either.
However, the only problem is I can't show you the photo as it has been lost in Swansea, even the copy printed off the machine in Boots. It was saved in a digital format on my sister's PC, but that was sold to Cash Generator. She never thought to ask if there was anything on there I wanted kept, and it was quite a long time afterwards that I found out too. She's buggered off to Ireland, and for all I care she can stay there permanently, I don't want anything to do with her whilst I still remember the loss of several hundred, if not passing a thousand, photos and video files.