What are the best cities in Spain to see the Semana Santa processions?

Semana Santa or Holy Week is held in Spain during the run-up to Easter Sunday. Celebrations and parades take place all over the country, but there are some cities that go all out.

What are the best cities in Spain to see the Semana Santa processions?
Semana Santa or Holy Week is held in Spain during the run-up to Easter Sunday. Celebrations and parades take place all over the country, but there are some cities that go all out.