For a good quality burger, cooked in the minimum possible time for decent food (i.e. not fast like McDonalds, but not anything like as horrible) Cosmo Grill is where you want to go. The beef is fresh, the ingredients well chosen, the burgers assembled with care using real food - who says fast food has to be bad for you. A burger costs just a shade under €8 and is IMHO good value at that price.
There's a discussion in the forum here: Cosmo Grill
Cosmo is on Falkenturmstr, just off Maximilianstr at the side of the Opera (Google map). Google gives an address on Maximilianstr which is misleading as the entrance is at the back of the building, on Falkenturmstraße.
Maximilianstraße 10
80539 Munich,
Germany
Telephone 089 89059696
Web: Cosmo Grill
Monday - Thursday until 3am
Friday and Saturday until 5am.