I highly recommend staying at Romina's place in Koukaki! The location is central, making it easy to get to attractions either walking or by train. Koukaki itself has a lot of cafes, shops, and bars to check out too. The space is large & clean, the air conditioning is very welcome if you're staying in the hot Greek summer, and check-in was a breeze via the lockbox. And Romina herself is very welcoming & communicative — we didn't meet in person, but she was quick to respond to all whatsapp messages and full of great recommendations for the area and Athens as a whole. Five stars!