World Class Art
Less famous than the Louvre and other european Museum's and a bit out of the way from the heart of downtown, but the Alte Pinakothek, the Neue Pinakothek and the newly finished Modern Pinakothek make up a juggernaut of art history and place Munich on the map as a must see location for art lovers.
Bear in mind that the Alte Pinkaothek is closed on Monday and the Neue is closed on Tuesday so if you wish to hit both in one day you will need to plan accordingly.
Recommendation for the Neue Pinkothek is to go in the exacte opposite direction of the recommended tour. This will assure you see the Monet, Van Gogh and other superstar impressionists. This is not to say that the rest of the museum was not worthy of viewing, because it's all jaw droppingly wonderful, but in the event that the Alte Pinkothek ran you later into the day than expected it may be helpful if seeing the big hitters is your priority.
Be sure to get the free audio tour equipment that is included in the 4 Euro admission fee.