While super-touristy, and super-crowded, this place is also super-fun! They cram people from all over the world onto these long tables, everyone sings along to the band (and gets drunk off of one-liter mugs of beer).
Went on my honeymoon. Took us 4 hours to find it (from Munich!) and by the time we got there, a thunderstorm with hail came down, sending everyone down the mountain! 10 minutes laters, the sun was shining and it was beautiful weather again. Gotta love the Alps.
Munich's biggest public square, is the centre of social activity in the city. Check out the Glockenspiele with cute figurines. Forget what time the figures dance, but you shouldn't miss that when you're there.