As Mia-Myklebust pointed out, Seattle is close to the ocean, lakes, moutains and even desert, if you journey a few hours East. read more
If you like culture, beautiful surroundings, great restaurant scene, healthy food, outdoor activities, open minded thinkers, tech vibe, start up culture, variety, fitness, and healthy people, Seattle is better. Dallas is significantly better for cost of living. Money goes a lot further in Dallas, especially in housing. read more
IMHO, the suburbs of Dallas are way better than the suburbs in Seattle, and aren't really even comparable. A more appropriate parallel to make would be between Seattle neighbourhoods and Dallas suburbs. Everything is much more compact in Seattle. read more