An affordable small apartment in a great location. We rarely used the public transport (which are close nevertheless) because the old town square and historical centre were only a 20-minute lovely walk away. The hosts had made an awesome notebook with recommendations for sights, restaurants (you should definitely try Karlinsky Mlyn, only a 4 minute walk away) and bars. Although, it was not the most comfortable stay, the price and the location should make it up.
Have fun in Prague!