The Noordermarkt is open every Saturday with a biological food market and every Monday with second hand clothes. Noordermarkt is loved because there a (almost) no souvenirs. This is a genuine Amsterdam market, like it has been for decades.
Besides food and clothes you can also find antiques, textiles, flowers, instruments, movies, vinyl and much more. In other words: A proper market full of surprises. The market is located next to the Noorderkerk (church) and surrounded by many bars which make a sunny day double the fun.
It's not really common to bargain on Dutch markets, but on Mondays you can still try.