I totally recommend Kaare Guesthouse! We stayed at Viljandi for one night just to relax, walk around and go to the theater. We chose Kaare mostly because it has sauna and the price was also reasonable. The apartment had all we needed and even more. It had fridge, microwave and all the flatware even corkscrew was included. We also had coffee, tea and sugar in our room!
The place was nice and cozy. Our room was very clean. Although the ceilings and walls were not that exquisite, the apartment was very up to date and neat.
The only downside may be the location as it is not at the city center. But in Viljandi there is no long distances and when visiting in summer you could easily go swimming to the pond few steps from the house.
We had very nice and romantic two days. Viljandi is wonderful in autumn.
Go to Viljandi and Kaare Guesthouse!