Depends. You should know when it comes to Comparing the 2 cities they are in 2 totally different metro sizes. Chicago is frequently called Chicagoland because of it's suburbs reaching in to Wisconsin and Indiana. While Seattle shares it's area with Tacoma and suburbs it's total area population including those is just over a million.
Weather.
Chicago is inclined to colder, snowier weather that will dip down into the negatives thanks to the lake effect phenomena .
Seattle tends toward a long rainy season with occasional snow and sunny days. Average lows are above freezing.
Traffic: While Chicago offers more in public transportation, trains and buses.
Seattle is implementing a new train system and has a good bus system as well as the ability to walk more places because of mild weather. Seattle freeway traffic has never seemed as cumbersome to me as Chicago does.
Outdoor activities and recreation
Chicago has it's lakes and parks and it's not far from some pretty beautiful forests if you're willing to drive some!
But when it comes to the Outdoors, Seattle is a gem! With artsy Parks and rec. Biking trails along the sound and beaches like Alki Beach, Dash Point and Lincoln Park you don't even have to leave the city to enjoy pristine beauty. If your more the woodland type, there is the Olympic mountains (which includes a temperate rain forest) The cascades offer beautiful vistas and hiking on Ranier as well as many other mountains and forests. You can Kayak, whale watch and so much more!
Bars and Pubs: Each time I visit Seattle I like to visit the local pubs. Seattle enjoys a rich and Diverse selection of breweries, bars, pubs and lounges. From dualing Pianos , corner irish pubs to aquatic dive bars, you're set to try something new or find your home away from home.
(I've never felt all that safe in Chicago when it came to bars so I've missed that scene. The key is I never felt safe...I feel safe walking around Seattle for the most part!
Arts and activities. Both cities boast a lot for the artist or the inspired. Seattle has a lot of first friday and second tuesday art walks as well as galleries both local and city, Seattle also boasts the Pacific Science center, the museum of flight, the EMP (expiremental Music Project) The space Needle, the Seattle aquarium, woodland Zoo and so much more.
Chicago also has second friday art walks, museums and Science museums, Navy Pier, Millenium Park, Shedd Aquarium , alder planetarium and the skydeck.
If you start to feel that both cities can be a place you call home try checking out rents on craigslist, each city has different price points.
To me, I love the mountains and the Ocean, I love the personal feel Seattle gives me, it's homey and stunning visually, the people, the traffic flow and the price are all reasons for me to choose Seattle over Chicago."
And as for Sports, Seattle also boasts several national level sports teams. Tacoma also boasts an Arena as well. There are no shortage of concerts, sports, shows, theatres (including IMAX) and things to do in Seattle. Being a landlocked person, I find the snow gets old FAST!