I was impressed with my stay at Hotel Arka. Its biggest asset is the absolutely perfect location, right on the main square and apart of the Old Bazaar. Within easy walking distance of all the major sights and restaurants. The hotel itself is euro modern and impeccably clean. My room was comfortable and well decorated, and I especially enjoyed the excellent and varied breakfast offered each morning. The staff were consistently friendly and helpful, providing great local tips. Parking can be a little hard as the carpark is shared with a few other locations. There is apparently a employee (not from the hotel) that helps locate parking spots.
For a central, comfortable, and well run stay in the heart of Skopje, I couldn't recommend Hotel Arka more highly.