I made a thing. This list includes all of the currently known steam train operations 15-inch/381-mm gauge or larger in the Anglosphere (US, Canada, UK, Ireland, Australia, and New Zealand) and grades them to see which are the best. It has 420 lines and 851 locomotives.

How it works:
Each railroad is graded on bell curves for the age of its right-of-way (older = better), the main line's length (longer = better), the track gauge (wider = better), how many working steam locomotives it has (more = better), and the age of its oldest steam locomotive (older = better). Lines with higher scores have a large scope from a technical and operations standpoint, and they tend to fully immerse you in another time and place better than those with lower scores. That doesn't necessarily means that those with lower scores are bad railroads; they're just small potatoes.

Discuss.