Greece — Top 5
Do the acropolis in the morning, ideally with a private tour guide, skip the museum but definitely visit the agora, check out Loverdos for a taste of Byzantine art in an old bankers mansion if you have time.
Feyrouz, fabulous Lebanese spot with fresh made pide, hummus and falafel
Treasure Island, vintage jean shop curated by a very nice Greek man who regularly does shopping trips to Milan and Paris
Material Primo, design forward wine bar-bistro in hip kouloukaki neighborhood
Της Θεατρου το Στεκι - Steki — small plates near Diporto
Mandragoras — technically not in Athens, this is a cute old school grocer over near the ferries, good for a picnic (dried figs, olives, cheeses) when on the way to an island