We went to Amsterdam this past summer to stay with a friend. He actually lives in Leiden a suburb 25 minutes by train outside of Amsterdam. we much preferred Leiden over Amsterdam. 1 day in Amsterdam was enough for us. it was dirty and crowded with tourists. Leiden, on the otherhand, is also called Little Amsterdam b/c it has a large number of canals and it is cute, clean and populated by Dutch...not tourists. 1 day we took a short ride into Amsterdam and another day we took a bus ride to the beach and went biking. that day we also stumbled on to the farmers market in Leiden ( on wed. and sat.) and we had some wonderful, fresh seafood and tasty fruit. Catwalk is a really good cafe with fresh sandwiches. it is by Rondvaart Canal Cruises on the way to Centrale station.
You might want to delete this post and put it under the "trip reports" section.
Amsterdam is a big city. If you dared to walk 10 min outside the 1st Canal Belt, you'd get away from most hordes and virtually all the seediness. Fortunately thye are cracking down on coffeeshops and brothels, the city municipality is actively promoting the gentrification of old areas (already worked out for the area around Remdrantplein) so in a few years, hopefully, the average party of drunk and stoned twenty-somethings will evolve into something else even there.