Tollwood
(http://www.tollwood.de)— very nice and relaxed festival with a large alternative market where everything is sold from asian interior stuff to hand made rings. the festival comprises several tents where music and theatre is played. while some performances are for free, tickets have to be bought for the major venues. you will also find lots of international food stalls and bars here. it's a great place to hang around. there's a summer tollwood which takes place in the olympiapark from mid june to the beginning of july for four weeks. the winter tollwood takes place on the theresienwiese from the last week of november until christmas. it's a great alternative to the commercial christmas markets.
Olympiaberg
If there is a concert in the olympic stadium and you didn't manage to get tickets or you think they are too expensive climb on the hill near the stadium. you will have a great view on the stadium and hear all the music. relax and listen to some great music with a blanket with you, some food and of course local beer.