Cycling: get your bike ready and go for a ride through Isar or outbounds of Munich. Here is the association that has all routes and maps around Munich: www.adfc-muenchen.de
If you are a master of cycling, plan a group trip to other cities.
Badminton: there is almost an every week meetup for playing badminton. You can create your own. Here is the place where you can go: http://www.sportzentrum-martinsried.de/
Basketball: you can play basketball outdoors (here are the addresses: http://www.munichhoops.com/ or indoors at different sport clubs.
Tennis: Olympiapark offers great facilities for tennis as well Englisher Garten (Tivoli)
Football: you can find great facilities to play football here - www.soccerworld-muenchen.de
Bowling: There are 3 main bowling places in Munich - http://www.dreambowl.de/standorte/dream-bowl-palace-muenchen-unterfoehring/; http://www.maxmunich-bowling.de/; http://www.olympia-bowling.de/olympia-bowling-muenchen.html
Golf: Munich offers around 6 different golf clubs. Here is a great place to learn playing golf - www.gcriem.de
Climbing: the biggest climbing facilities (indoor and outdoor) can be found here: www.kletterzentrum-muenchen.de
Ice-skating: invite your friends to enjoy ice-skating here: www.olympiapark-muenchen.de
Roller-blading: The areas along the Isar, the northern part of the English Gardens and the Olympia Park are particularly popular. There’s also a lovely circuit just outside the city at SchlossSchleiß-heim (S1 Oberschleißheim). More info: www.skatemunich.de, www.inline-strecken-fuehrer.de, www.muenchnerbladenight.de
Running: you can organize spontaneous jogging through the Englische garden or get involved with Club: www.mrrc.de
Sailing: courses and facilities you can find here: www.ammersee-segelschule.de
Hiking: great ideas for hiking trip with friends can be found here: http://www.newinthecity.de/en/sports-leisure-munich/nature-excursion-munich/hiking-munich/2720-the-most-beautiful-hiking-trails-near-munich.html