You're choices come down to Frankfurt or Munich, unless one of your choices is Berlin.

I'd pick Munich over Frankfurt, although I like Frankfurt. There's a lot to do and it's a pretty city.

I'd pick Berlin over Munich because I love it.

Bill; Tell us where you are flying into and out of so everyone can help.

So far, it does not sound inviting for only two days in Germany.

Many of the airlines flying from US to Italy fly through either Frankfurt or Munich. We probably won't be going back to this area so we thought we would take advantage of the opportunity and tour a city for a day or two.

Out of the three I'd say Munich is the most approachable, but I don't really like the big cities and suggest you also look at Berlin followed by a drive to Leipzig, Dresden or Magdeburg. Of these Magdeburg would be a real shocker as it embodies
Otto's empire
East German structures
Very affective public transport
Very affective bicycle culture
Some fascinating history, buildings and visitors sites

Bill44, after you visit Munich you may change your mind.

You can do quite a bit in Munich in a small amount of time. Enjoy your trip.

Munich would work. Easy train ride into the city center.

We stayed in a Westin just outside the train station and it was an easy walk to the old city center.

We did use AX Starwood points. Or points and dollars.