Pennsy, pre 1953, when passenger motive power was painted the proper DGLE. Why? Partly because there is a model of virtually every 20th century loco. And, tons of information.
2nd--B&O, the plucky striver against Giganto.
3r--N&W-who doesn't like N&W?
4th--Reading. Bought a Lionel T-1 y'ars ago. Just a cool railroad.
Thank heaven that I'm out of storage space, else I would be bankrupt...