The question is very tourist and subjective. =) Of course, I like walking around the historical center, next to Marienplatz, but there are many other interesting places that I like. 

For example, opposite the Deutsches museum (which you must visit, it will be interesting to everyone) there is a Gothic cathedral, which resembles a castle, with two beautiful towers

Just next to this place is very cool to sit on the river bank on a sunny day. The river is also very beautiful and fast, called Isar. People say this is a mountain river and I willingly believe them. Also In the Englischer Garten. There is a fast river, so fast that in summer there are people surfing 0.o… 

In Munich, almost 90% of the streets are very beautiful and it’s nice to walk there. One of these streets is Nymphenburger Str. It is possible to exit this street from the city center as well. There are not many tourists and you can just see how people live in the city.

Olympia Tower seemed to me a bit boring, so I recommend going to the observation platforms in the center of the city is much more impressive. But if you have a lot of time, then I advise you to walk around the city without a map. You can accidentally find amazing things!

Anna