In Valladolid we stayed in a hotel from the Nh chain - Nh Ciudad de Valladolid. It is a comfortable 4 star hotel, located outside the city centre on a residential neighbourhood. It is also situated by an Exhibition Centre, therefore I assume that when major Fairs and Exhibitions take place it might get over booked. Service is good, the staff is helpful and rooms are very comfortable. It also has private garage.
Maybe one of the best options quality-price, although you have to cross the river to arrive to the city center (10-15 minutes walking). New hotel, NH style, full of small details.