This series will precede from memory, listing the first strong impression to the least that comes to mind. Any need to rack my brain ends the list.
From most to least impressive, seen from a passing train:
-California Zephyr, Chicago to Emmeryville, California, train lines are 5 and 6, Central Pacific
-Empire Builder, Chicago to Portland/Seattle, train lines are 7 and 8, Northern Pacific
-Coastal Starlight, Los Angeles to Seattle, train lines 14 northbound [and 13 or 15] southbound
-Capital Limited, Washington D.C. to Chicago, #29 westbound, 30 eastbound
-The Pennsylvanian, Philadelphia to Pittsburgh, #43 westbound, 42 or 44 eastbound
-1. Steven’s Pass, Washington in three feet of snow, westbound to Seattle, Empire Builder
-2. Above White Fish Montana, eastbound to Chicongo, Empire Builder
-3. Columbia River Gorge, morning view of Mount Hood approaching The Dalles, westbound to Portland, Empire Builder
-4. Donner Pass, California, eastbound and westbound on California Zephyr
-5. Colorado River Gorge, eastbound and westbound, California Zephyr
-6. Glacier National Park, south of, eastbound to Chicongo, Empire Builder
-7. Book Cliffs, near Grand Junction Colorado, westbound, California Zephyr
-8. Approach to Grant’s Pass, lakes and distant volcanic mountains to west, northbound to Pacific Northwest, Coastal Starlight
-9. Grant’s Pass, switchback descent from arid mountain range into temperate rain forest, northbound, Coastal Starlight, best view to the east
-10. View of the Great Plains over Denver, emerging from the 8 mile Moffet Tunnel at ten thousand feet—a mile over mile-high Denver, Eastbound, California Zephyr
-11. Granby, Winter Park and Frazier Colorado in spring affords best wildlife view from train, California Zephyr
-12. Morning view to Washington D.C, on Capital Limited atop the Appalachians in Western PA, Western Maryland and West Virginia to Harper’s Ferry, eastbound only, this portion a night train westbound to Chicago, the longest scenic view in the east, headed east
-13. Horseshoe Curve, above Altoona PA, from The Pennsylvanian, morning eastbound and afternoon westbound
-14. Susquehanna River crossing, Pennsylvanian, more impressive then…
-15. Mississippi River crossing on California Zephyr at Burlington, Iowa
-16. Scrapyard Mississippi River crossing on Lincoln Service and The Texican at Saint Louis
-17. Susquehanna River crossing on Capital Corridor from New York to D.C. at Havre de Grace, Maryland, more impressive, again, than the Mississippi crossings
-18. Truckee River Gorge between Donner Pass and Reno, Nevada, beautiful views for two hours from snowy mountain evergreens to desert stream east, and the opposite climb west, on the Zephyr
-19. Bay Crossing to Martinez, California on Zephyr and Starlight
Views by Line:
Zephyr: 9, mostly long views
Empire Builder: 4, all long views
Coastal Starlight: 2, long views
The Pennsylvanian: 2, one brief, one long view
Capital Limited: 1, long view of many mountains and towns from a relative high elevation
Lincoln Service: 1 brief view
Capital Corridor: 1 brief view