Deschutes is my favorite brewery!! If you go, try the Black Butte porter, and if its on the menu, the Mos Eisley. Its unlike any other beer I've ever had. They might have their Black Butte Porter 27th anniversary edition, which is excellent. VERY thick, lots of flavor... Man, I had to read this while I'm at work :'( Now I want a beer... There's also their Extinction Stout, which is brewed with Raspberries of all things. It has an aftertaste of chocolate covered raspberries, which is pretty cool if you like that kind of stuff. I'm not a huge fan of them, but it was a very different flavor and worth trying :P
There are a few others I've been to down there, Coalition, Bridgeport (they have a good IPA if you like that style, I personally don't) Hair of the Dog (they're one of the top rated breweries on RateBeer.com) Full Sail, Hopworks... I love portland.
Here's the top 50 beers on RateBeer... Looks like Deschutes got on there with their The Abyss Imperial Stout!! I usually use this website to find breweries worth visiting when I'm on vacation.