The main area, and central to most tourist spots, is Syntagma Square. This is a large area of the city with lots of shopping, cafés, and government buildings. It is probably one of the nicest areas of Athens (see? I can say good things about it). It is also the starting point of the two competing “hop-on, hop-off” bus tours. I highly recommend this because not only is it a good way to get to the key destinations, it is a way of avoiding the jam-packed metro. Also, because they are competing side by side, just say you are going to be in town for three days (if you are) and they will validate your ticket for that long, even though it is only supposed to be for 24 hours. I definitely got my 18 euros worth from this.
The hotel where I stayed, the Novus, was a stylish boutique hotel. Everyone was very accommodating and helpful, especially with the ferry fiasco. They serve a nice buffet breakfast and have a rooftop pool and bar where you can also get a meal. Here are a couple of shots of the view, the Acropolis and the pool: