I’m flattered, but hardly a train expert having only done two major trips. They were fun though - love the relaxing ride and scenery. From what we have done I agree the CA Zephyr is superb. The Southwest Chief and Coast Starlight are also worthy. We’re looking forward to doing the Empire Builder sometime when we can fit it into our travel schedule - perhaps next June"ish."
One train I’d love to do, but we have to plan it a bit more is the Rocky Mountaineer. It’s not Amtrak, but a Canadian line operating in the US:
It does all of the most scenic section of the Zephyr, then cuts down into scenic Utah and travels solely during daylight hours so you miss nothing, plus don’t have to adjust to sleeping on a train. Amtrak doesn’t go down into Utah where this does. It only cuts across the state. We’d take Amtrak to Denver, then switch I suspect.
Otherwise, I wrote a trip report about our most recent trip on Amtrak here with pics in later posts: