Fremont Cowiche Canyon Organic Fresh Hop Ale: one of the best beers most people have never heard of Fremont Seattle Beer Week 5th Anniversary Organic Pale Ale: brewed for this year's SBW, damn tasty Hopworks IPA: one of my favorite IPAs on the planet, I should buy more of it
I've enjoyed a good portion of the Peak Organic lineup. The beers don't get much talk here. The IPA, Summer session and Oak Aged Mocha Stout are my favorites. This is tasty as well: http://beeradvocate.com/beer/profile/119/14172
Ive tried one of the Bison Organic beers, their Hop Cuvee. Not bad, nothing stellar but It was pretty tasty. http://beeradvocate.com/beer/profile/609
I concur with draheim that Hopworks IPA is terrific - one of my favorites, too. I'm also a big fan of their Seven Grain Stout. In fact, everything the brewery makes is certified organic. Same with Logsdon Farmhouse - all organic If you really want to go all out trying organic beers, plan a trip to Portland the last weekend of June for NAOBF
Peak Organic Espresso Amber surprised the heck out of me. Really enjoyable. I second the Oak Aged Mocha Stout as well.
Cowiche Canyon is so good I wouldn't care if it wasn't organic, made by Monsanto, and brewed using cooling water from the Fukushima nuclear plant. Fish brewing in Olympia has an entire lineup of organic ales. http://beeradvocate.com/beer/profile/684
The whole Samuel Smith Organic line is incredible and should be had by any fan of beer. Summit Unchained #12 Organic IPA is f'ing fantastic, too.
Part of the Samuel Smith organic line up is the Pure Brewed Organic Lager, which is a great summer beer - highly recommended.