And let me tell you it is celebrated quite differently from other parts of the world as well. It is tradition for groups of men (young and old) to go on some kind of hiking tour with one or more 'Bollerwagen' (handcarts) to carry their beer or other alcoholic drinks. Some of these carts are specially built or decorated for this day only.
A lot of beer breweries do some special advertising just for Father's Day unfortunately they loose their wit and humour when translating them.
However I came across this old Durex advertising from 2005 which I think is quite funny.
Happy Father's Day!!
[via wikipedia, wikimedia, meetinx]