We stayed at the Central hotel in Athens this time last year. About 2 blocks from syntagma square (where the airbus stop is) and near the Plaka. Newly renovated, clean. The only downside was the very small lift. We booked thru booking.com. Lots of good restaurants all within a 10 min walk. Lovely rooftop bar overlooking the Acropolis - very popular at sunset.. HTH