So, I'm going to give you a crucial piece of advice for anyone who's going to Athens, and no, it's not "put some sunblock" which you should, the advice is to stay at Panagiota's.
There's everything and anything you might want there, an amazing host (kind, smart and thoughtful ) good location (literally 1 minute from the Acropolis, 0 minutes to the flee market and 2 minutes to the metro station), a beautiful place (it has a big terrace from which you can see the Acropolis, as well as the Temple of Hephaestus, great rooms), a safe place (about 10 minutes to Syntagma square, which means it's walkable 24/7, or at least in my experience up to 3:30 am) and comfort (it really is super comfortable).
If you're in Athens, alone, with friends, family or with your couple, it's perfect for you.