One of the oldest city-resorts of Bavaria is Bad Aibling which is situated in an hour drive from Munich and in the same distance from Bad Reichenhall. You can look at the city on the map here.. here, and the resort was started to build around them. The town is small, the population is only 18 000 people, it is a part of the area Rosenheim. There are no attractions in the city except thermals and aqua park.
However, those who will go there by car should pay attention to this city because of its convenient location. The city is practically stands at a road junction Munich – Salzburg, Munich – Innsbruck, which makes it possible to travel to these wonderful cities, and come back in the evenings to relax in local thermals.
There is not a big variety of hotels and guesthouses, so you should book in advance.
I would also recommend you to pay attention to the wine stores, where the drinks, made from grapes raised in these places, are sold, and there is a farm for breeding trout (so even yummy!).