Based on a several day trip to Amsterdam in the early 2000s.
Amsterdam is a great city, one of my favourites in Europe. I love the maze of canals and the fact that everybody in the city is walking or riding a bike. The truly liberal spirit in the city is also great, there are many young and open-minded people and pretty much everybody speaks English. The nightlife is also very good (the smell of pot will constantly remind you that you are in Amsterdam...). In addition to the typical things that tourists tend to do in Amsterdam (smoke a joint, go to the red light district), there are great museums like the famous Van Gogh Museum. An ok hostel in Amsterdam is The Flying Pig hostel (you can also work for them in exchange for free accomodation, in case you would like to hang out in Amsterdam for awhile).