There are a lot of micros here to choose from. Some of the best include Hair of the Dog, HUB, Deschutes, Ninkasi and Upright. A good bet is to go to a beer bar such as Horse Brass, Green Dragon or Bailey's where you can try a varied selection. about 10 years ago
in my experience, bars that have a varied selection of beers tend to have better food and atmosphere than the breweries themselves. however, there are an endless number of great breweries around, as well.
check out this site: http://www.urbandrinks.com/happyhour/usa/or/portland
i don't know what area you're in, so i'll just give suggestions for two regions of the city: north and northeast. here are some places that have a wide selection of microbrews, as well as ok food: alberta street pub and alameda brewhouse, concordia brewhouse, county cork, mash tun, amnesia, prost, lompoc 5th quadrant. see the link above for other areas. you really can't go wrong looking for microbrews in portland! about 10 years ago