I can highly recommend Casa Bella Suites in Nairobi. I spent a week there in November 2012, and when I left, I was saying goodbye to friends.
The managment and staff is very helpful and friendly and you feel genuinly at home at Casa Bella.
The rooms are spacious and clean with satellite TV and free Internet Access. Good breakfast and the neighbourhood both quiete and safe.
I give Casa Bella the highest rating and will definitely return to stay there again.