The Nerva Accommodation is a fantastic place to stay in Central Rome. It is directly out front the Cavour Metro stop, one down from Termini Station. It's about a 5min walk to the Colosseo and walkable to many other attractions. The street its on is lively with good food and bars.
The accommodations are hotel like, air-conditioned, very clean, towels, shampoos, daily cleaning service, etc. It's a great value for what you pay.
I would absolutely stay here again and recommend it to anyone else.