The The folks over at "appfog":http://appfog.com/ have put together an extensive argument for why Portland could be the best city in the United States for developers.... and covered a lot of compelling things related to the local developer ecosystem.
Having said that... they missed everything around Portland that makes me stay in the area. All the hiking within "60 miles of Portland":http://www.amazon.com/60-Hikes-Within-Miles-Including/dp/0897329759 (there are even several trails within the city limits!), all of the rivers for kayaking, windsurfing, the snow resorts, all of the camping and backpacking that we can explore... etc.
Outside of getting immersed into your craft, it's nice to get out of the city to ponder those technical challenges while on a hike.