The Coast Starlight, with its often-spectacular views of the Pacific Ocean, takes passengers from the Los Angeles area to Seattle. This train trip is for outdoor lovers, but watch out--you could make a lot of stops. Get views of California's wine country and redwood trees, the Cascade and Sierra Mountains, and check out the area's most vibrant and cultural cities, like San Francisco, Eugene, and Portland. If you don't stop along the way, the trip should take about 35 hours.
Called one of the most beautiful train rides by Amtrak riders, the popular Zephyr train winds from San Francisco through the Sierra Nevada Mountains, the Rocky Mountains, Salt Lake City and Denver before ending in Chicago. The route offers endless opportunities to see some of the wild country of the U.S. The train makes stops at some of the country's most noteworthy national parks through a partnership between Amtrak and the National Park Service called Trails & Rails. Without stopping for a scenery break, the trip is about 51 hours.
The Capitol Limited gives a whistlestop tour of the industrial northeast--from Chicago to Cleveland and Pittsburgh, and on to Washington, D.C. This route puts you in touch with historic sites like Harper's Ferry and the Potomac Valley. If you do the whole trip without stopping, it takes about 18 hours.
If you're going to be traveling by train overnight or for a long period of time, consider a sleeper car. All the routes mentioned above offer sleeper car service, and it's well worth the extra money. In addition to an actual bed to sleep on, Amtrak's sleeper services give you more overall creature comforts, including showers, fresh towels, the daily paper and complimentary food. On a long trip, these extras can mean the difference between haggard and happy. One note: sometimes sleepers are available at cut rates after the train has left the station. If you forget to book a sleeper, ask the conductor when you get on the train.
If you do find yourself wanting to stop along the way to see the sights, book yourself a multi-city ticket. Amtrak does allow you to do this, but it's much easier to set up ahead of time.