Yes, it's a tourist trap and every guide book recommends a visit, but the Hofbrauhaus in Munich's old district is wonderful. It is indeed unmissable because the atmosphere is great and the beer is even better. It has room for hundreds of people in a vast set of chambers originally built in 1896. The food is good and served promptly but bear in mind that the beer, Hofbrau naturally, comes in quantities of a litre or more - there are no half measures!
One's fellow drinkers are good humoured, ready to talk and have a good time, and there's even a traditional Bavarian 'oompah' band which strikes up every five minutes or so, but curiously fails to play a complete set. Perhaps the players need regular topping-up with Hofbrau and that interrupts their performance.
www.hofbraeuhaus.de/
Hofbrauhaus, Burgstrasse, Munich. S-bahn Am Platzl 9
+49 (0)89 29013610
Google map: bit.ly/QtC6ch