Although convenience in location is just one of the positive aspects of Haus Trausner, I thought I'd mention that to add to everyone else's rave reviews!
If you're travelling to Hallstatt by car, consider the fact that you can't drive into the town. You park your car on the outskirts and then catch a shuttle bus, or walk. If you stay at Haus Trausner however, parking is available at the house.
Travelling by bus? This is the closest accommodation to the bus-stop... 5 minutes walk.
Travelling by train/ferry (as I did)? Then it's a 10 minute walk or shuttle bus to the house.
If you plan to self cater at all, the town's super market is opposite the bus-stop. Maria provides tea and coffee making facilities as well as a small fridge.
I'd now like to endorse every positive point everyone else has made! Maria is a genuinely warm and welcoming host who will help you make the most out of your stay. I stayed for a week and could easily have found activities to fill more time.
Hallstatt is a uniquely beautiful town with a fascinating history dating pack to prehistoric times, while the preservation of the local culture and dress is a fascinating aspect of modern Hallstatt.
Now, perhaps you're wondering, like I was, for €35/night for a double room (single use, with ensuite shower and basin but shared toilet, table and chairs), including breakfast (compared with €80 for a similarly sized room in other accommodation houses), how good could it be? Can I tell you it was perfect! Perfectly clean and fresh, beautiful outlooks from all the rooms and a welcoming place to come home to at the end of a day's adventuring!!