Santorini isn't exactly famous for its beaches, the towns and villages more so represent an unbelievably crisp view of day to day life or to enhanced perspective of sunsets over cliff edges and the Caldera.
But if you are going to spend any time hunting down a place to dip your toes in the sea, you may enjoy Red Beach a little more than others.
The rock is colourful and although it is a pebble beach, it's quite comfortable.
The only real draw back is access. Unless you're arriving by sea arriving at the beach requires a car and driver or public transport into nearby Akrotiri, then finish the journey on foot via unofficial, loose rock pathways.