I have a single night to spend in this big, beautiful city. What area? Is there a section that is more quaint and Old World?
I'd say around the Viktualien Markt. Like a lot of German cities, Munich had the crap bombed out of it during WWII, so mostly it is restorations with modern interiors for a lot of buildings.
The Platzl Hotel is a 3 minute walk to the Marienplatz, the heart of the Old Town. Stop and have lunch and a piece of cake at Richert, very close. And there's a lovely shop that sells handmade wood crafts (nativity scenes at Christmas, hand-painted eggs and such at Easter) that is also along this short walk. http://www.platzl.de/
We just returned from Munich last week and the only hotel we use is the Hotel am Viktualienmarkt. Great family run hotel half a block from the Viktualienmarkt and the Marienplatz. Check them out online. :)
By all means, stay at the Cortiina Hotel! It is in the Old Town area. I watched Samantha Brown in Munich and stayed in the same hotel. It was wonderful and just a short stroll to a wonderful little spot for dinner. The staff there was great. We walked around and saw the sights and shopped all within a short walking distance to our hotel. Great for a short stay and they also have apartments for larger parties or longer stays. The only thing I would have improved was a softer pillow. Otherwise a perfect stay!