I really recommend the Ibis Edinburgh Centre mainly because of the location and great value. The hotel is in the heart of the historic part of the city, just few minutes from the great attractions such as Royal Mile, Edinburgh Castle and Holyroodhouse Palace. Besides this, it is also near pubs, cafes and restaurants of the old city. However, if you prefer to walk along the Princess Street region, the hotel is not so far, so you can go by walk (but in the return to the hotel, you will have to walk in a steep street) or by cab once the price is reasonable. The en-suite rooms are normally simple, but with enough comfort for a couple. The prices, if you book in advance, can be compared with the hostels. I believe that is a good option in the city.