Cafe de Pijp is perfectly located on the Ferdinand Bolstraat with a nice sunny terrace - great for people watching right in the center of the Pijp. This cafe is more upmarket than a typical brown cafe, but still serves no nonsense food in a friendly atmosphere.
This is where real Amsterdammers go for a drink. If you've heard of the after work tradition of a "borrel", then this is where to do it. The only 2 words of Dutch you will need are "bier" and "bitterballen" (untranslatable Dutch snack!) - "graag" (please) is optional!
If you want something more wholesome, I can recommend the BLTG - bacon, lettuce, tomato ... and guacamole!