Of course it's a matter of taste, but for me it would have to be the Meseta, Burgos to Leon.
The best hostels, many of them donativos:
Trardajos, San Anton, Puente Fitero, Santa Maria in Carrion, Domenico Laffi in Carrion, Santa Cruz in Sahagun
Great cities, towns and villages:
Casterojeriz, Moratinos, Sahagun, Leon
The place names:
Rabe de las Calzadas, Boadilla del Camino, Revenga de Campos, Terradillos de los Templarios, El Burgo Ranero
The open churches. The sweeping magical countryside. Peaceable Kingdom. The gut-busting hill outside Casterojeriz.
The Brazilian music tape in the cafe in
I understand that there are people who take a bus across the meseta because it's boring. It takes all sorts. For me it's the heart and soul of the Way.