Go to the "Backstage" (for rock/ragga/electro/concerts - depends...)
or to the "Garden Club"
or the "Muffathalle"
or the "Babalu"
or "The Atomic cafe" - of course. ;-)
Visit one of the many brilliant museums, e.g. the "Pinakothek der Moderne" or the "Haus der Kunst"!
If your german is good, you can check out a play at one of the great theaters, e.g. the "Kammerspiele".
hell there`s lots and lots to do. If you want to check out more, go to