Washington: The Big Picture
Seattle is a great place to live. People here are very laid-back, but still very active. There is much to do outside the city, including hiking, camping, skiing, kayaking and boating, as well as plenty of high-end shopping, restaurants, clubs, bars, theater, music (Seattle has one of the top Jazz scenes in the world) and organizations within the city. The area around the university provides a lot of support for students in terms of housing, cheap and diverse food, and part-time jobs. The crime rate in the area is low compared to most other urban settings.
One thing to keep in mind, though, is that UW is a very large school. While this can provide a lot if you're unsure what you'll be doing with yourself, it can also make you feel a little lost, especially when first starting out.
UW is one of the top research universities in the world, and thus a lot of its energy and focus goes into its graduate programs. Many undergrad students feel as if they are being marginalized by this attitude...on the other hand, it means your TA's are usually top-quality. Many of the more specialized classes like English and philosophy still have small class sizes, too, and are often offered in multiple sections--enabling you to choose the schedule that works better for you.
Washington Academic Life
Competition in many classes is high, especially if you'll be taking the same ones as pre-med and pre-engineering students. But once you make it past the big intro courses, you'll find your professors and TA's very helpful and engaging. And there are a lot of organizations like CLUE that are specifically taylored to helping floundering undergraduates.
Your relationships with your professors will improve as you move into being an upperclassmen, since more of your classes will actually be taught by professors. Many departments have their own sophomore- or junior-year admittance processes, so once you've been accepted to the department the profs are much more open to you. I'm in a very small department (Chemical Engineering class size: 40-60), and all of the professors know us by name. They socialize with us often and most have open office hours.
The faculty, and thus the classes they offer, are diverse. Student participation is encouraged, and generally you'll find plenty of people willing to step up and talk. Competition is usually high, but not overwhelmingly so. A good school should provide a good--but not impossible--challenge, and I think the UW does that very well.
Washington's Student Body
Racially, UW's student body is mostly white and Asian. There are a lot of different religious groups, predominantly Christian, but also substantial numbers of Jewish, Muslim and Taoist organizations. There is an active LGBT community, and people from all social classes attend the school.
The way the school is structured allows for plenty of inter-community interactions, although I have always seen substantial segregation of black and immigrant students. There are subtle but definite racist undertones in these groups, and it's difficult to tell exactly where they are coming from. The school itself is very non-discriminatory. There are a large number of public dining halls and more private meeting places, huge libraries, department lounges and lobbies, community centers and outdoor/recreational areas that provide great opportunities and setting to meet people. If you're open, you'll definitely find others who are, too.
The political climate of Seattle tends to be very liberal. To be honest, the campus republican organization is kind of a joke...but so is the LaRouche PAC. People are usually pretty laid-back, however, and passionate/violent demonstrations are rare.
Washington Student Activities + Social Life
The UW has a HUGE number of organizations, more than I could ever hope to name. If you go out looking for it, you'll probably find it. There are recruiting posters everywhere, and most organizations "table" near the HUB or in Red Square, the quad or anywhere else the UW will permit.
The dormatories are primarily for undergraduates, although there is a designated "quite dorm" that has single rooms and kitchens, intended for those students who really need a quiet and calm place to study. In the undergraduate dorms, people tend to leave their doors open often. They like to play pranks and throw parties on the weekends. The quiet dorm is obviously much calmer.
But most of the partying happens up at the fraternities and the houses off-campus. Rush is a big event every year, but there's enough separation between the frats and everyone else that you can completely avoid them if you want to.
I'm at a point in my major right now where I don't have any free time. In fact, I feel like a big slacker for taking some time to do this survey. I'm working at my department building all day, every day, including weekends. But occasionally me and my classmates will go down to Finn McCool's Irish Pub and unwind with $3 wells or half-price pints.