Regional trains are the best seats in the country
Express trains get you there; regional trains show you where you are. They stop in villages that do not appear on tourist maps, the windows open on older carriages, and a ticket rarely costs more than a coffee and a pastry.
A few favourite stretches
The line along the Vltava south of Prague, the single track through the hills near the German border, and almost any branch line in South Bohemia in late summer, when the fields are cut and the ponds are full.
Bring a book, sit on the side facing the river, and do not plan a tight connection at the other end.