I've been to Amsterdam twice now (just got back a few weeks ago, actually). The first time, I found Golem, which quickly became my favorite bar.
This time, I found a new place through a Red Light Walking Tour given by Mike's Bikes. (I highly recommend their bike tour to the countryside, their red light tour was good too.) I didn't remember the name of the place, but the pictures from google maps tell me it's "Nederlands Biercafe 't Arendsnest" on the street Herengracht 90. ([ame="http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=amsterdam+dutch+microbrew&vps=2&jsv=168d&sll=37.0625,-95.677068&sspn=28.334641,79.013672&ie=UTF8&cd=2&ei=0dRsSoTyI4yO8gTEmJmMAg&usq=dutch+microbrew&dtab=0&cid=8659992894988214724&li=lmd"]Link here[/ame])
They had many dutch microbrews. Our tour guide told us that, apparently, some Dutch brewers have been taking tips from American micro-brewers. I got a very hoppy ale which was very good. Not actually that bitter, but loads of hop flavor. You should check it out!