Rio's studio apartment was perfect for me as a single traveler. Having a kitchenette available and a supermarket only a 1 minute walk away meant that I was able to save money by cooking meals rather than eating out all the time. (And having proper ground coffee provided was a bonus!) The DVDs were also very handy for the evenings.
The apartment is only a 10 minute walk from the main attractions - TIP: if you walk to the Temple of Zeus, there's a hop on hop off bus stop that will take you round all the main places - 18 euros for 2 days of travel.
Thanks Rio and Maria, I had a wonderful time in Athens - I reckon it was the favourite bit of my European tour!