As good our our Rick Steves book was in Istanbul, in Athens it gave us new places to look forward to every night for dinner. While the walks made interesting reading, we'd already seen every museum but the Byzantine on prior trips, and we knocked it out the first afternoon we were there.
We were staying in the Plaka area, so everything was walking distance, and the two best places, he counseled were on the Mnisikleous street "restaurant steps" a sidewalk that was inclined steeply upwards towards the Acropolis. It was just a few blocks away, so after having dinner the first night at our old favorite, Hermion near Cathdral Square (where we always had lunch) we tried what looked like the two best places our last two nights.
The first night was at Geros Toy Moria (I think), not quite at the top by far enough up that you had a nice view down the grapevine-covered arbor overhead from our table on the steps. Fresh bread, olives, feta, rustic wine, and good Greek cooking - it was magnificent. They started dancing in the taverns below us around the time we were headed home, and you could tell it was a good spot for night life. But we're pretty much just there for the food.
But the book was definite that the best experience was at a restaurant that is almost concealed at the top of the steps, and that is Xenios Zeus. I got a 500 ml terracotta jug of cheap wine, we got the #1 (or was it #2) plates, which consisted of multiple appetizers and sauces, the best grilled bread I've ever had in my life, and again, I can't remember the specific foot, but probably lamb or kebabs or some plain and lightly seasoned. And then watched the sun setting over Athens to the north with our table pushed up against the trees at the base of the rock of the Acropolis. The owners sat and visited with patrons while we were there, and it was - as the book said - obviously a family-run joint.
This night-time photo isn't from our trip, but the table in the foreground was ours.
So I can't recommend the Mnisikleous resturant steps enough. Just be sure you make it to the top at least one night.