I've traveled on these with Amtrak: City of New Orleans, Lincoln Service, Empire Builder, California Zephyr, Southwest Chief, Cascades, Crescent, Capitol Limited, Coast Starlight, and Texas Eagle/Sunset Limited. And hopefully many more to come!
And I've traveled on these routes, pre-Amtrak: Empire Builder (Great Northern), North Coast Limited (Northern Pacific), Abraham Lincoln (Gulf, Mobile, and Ohio), City of Hinkle (Union Pacific).