We had a very nice experience at Ridolfi guest house in Florence. We stayed for 4 nights in September. They have a nice but simple breakfast served between 8 am and 11 am, clean rooms, clean bathrooms, and free high-speed WiFi internet. Also, our room was huge!
It's an easy 10 minute walk from the train station and in a very good location for getting to tourist attractions.
The staff is only there during normal business hours, but I found I could reach them after-hours via e-mail if I had any questions.
This was a nice place to stay and I'd recommend to others, especially considering the great price.