I was there a couple of years ago during Octoberfest so we were somewhat limited. However we stayed in Moosach which is roughly halfway from the airport and central Munich right on the tramline from the airport.(It is a about a 20 minute ride to Marienplatz station from there)
It is a small district with authentic German bakeries and restaurants all within walking distance of the hotel we stayed at. It is only a 5-10 minute subway ride to the Olympic Village and the BMW museum, perfect for me, no so much for my wife. If you are there for 4 days I would recommend you get a week pass for the transit system, it gets you on both U-Bahn or S-Bahn systems.
hth...Mike