You have definitely to stay at one of george's apartments. DEFINITELY.
A quiet place, near everything, 1 minute away from monastiraki, walking distance from acropolis, plaka, ermou street, syntagma, market, you dont have to use public buses or metros if you stay there. Excellent staff and hosts, they help you whenever you want, very clean, you have in the apartment a kitchen with all stuffs that you can use, you have smart tv with internet and netflix, free wifi. George is very nice he responds 24/24h at your requests.
Don't think twice, it is a excellent choice Highly recommended