If you want to visit and enjoy a normal resident life, out of the Athens Down Town tourist area, in 10-15 minutes walking distance you can enjoy to the most famous non-tourist spot, the square Fokionos Negri.
Fokionos Negri is an area full of green, car-free, with restaurants, coffe shops, fast food, pizza, grills, fish taverns, Varsos etc. In this area, everything stay open until late at night, every day. Even at 2:00 after midnight you can meet people outise, or find a restaurant to eat, or a night bar for a drink.