Everyone takes buses or drives to Santos, but there's actually a scenic boat route that runs weekends from Porto de São Paulo. Takes longer but you get incredible views of the coastline and industrial areas you'd never see otherwise.

R$85 for the round trip, includes refreshments. Runs Saturdays and Sundays only, departing 9 AM. Book through their website - it fills up during summer months. Much more relaxing than dealing with highway traffic.