I always tell my friends that there are two times of the year that are perfect to visit Munich - during the Christmas Markets and during the Oktoberfest.
Also known as the "fifth season", the Oktoberfest makes the city shine with a special light. Everybody seems to be in a good mood, meeting up with old friends and family and very elegant in their Tracht, Lederhosen for the men and Dirndl for the ladies.
For three weekends in the end of September - beginning of October, every year the Munich people commemorate the marriage of Ludwig from Bayern and the Princess Therese from Sachsen-Hildburghausen. What started as a celebration with a horse race at the Theresienwiese, turned out to be the biggest popular festival in the world.
It is an spectacle to watch, specially in the first two days, where numerous parades take place and on the last day, where the closing hours are lots of fun and even emotional.
The fest is divided into tents of the most popular beer houses of Munich. The rule is that only beer that is brewed inside the city can be sold in the Oktoberfest.
Some of the most popular tents are the Augustiner, Hacker-Festzelt, Hofbräu, Paulaner and Marstall, where only beer and food is served. There are also other tents where you can have sweets, like the Café Kaiserschmarrn or Bodo's Cafézelt. And then there are two lovely tents (which are my favourites) where you can have delivious food, wine and the best desserts: the Weinzelt and Käfer.
Of course it is important to know which tent suits you best, as each one of them has a different atmosphere (some are more turistic, some more posh, others more for families, etc.)
You can get an idea in this funny video from Harry G:
And some tips about how to drink a Maß:
More links and fun readings: