Hotel Tempi

I booked the Hotel Tempi because it was highly recommended in the Lonely Planet Greece Guide. And despite of being a basic hotel with no lift, no breakfast and almost nothing but the bed and the TV, it is a nice place with great views to the Acropolis and a great location near almost every interesting place in Athens.
The staff of the Hotel is really nice and they allow you to leave the luggage there after the check-out for free.
The street in which the hotel is located is very quiet and nice, with a flower market just in front of the hotel and the church of Agia Irini. The price for a double room with bathroom in the low season is 45 €, not bad at all.
They also have a kitchen for the guests where you can cook you own meals and they give you information about travels to Mycenae and to the islands.