I went to Washington State University (8 miles west in Pullman, WA
as previously mentioned) and loved the experience. I still visit the Pullman/Moscow area regularly, living in the Boise area now.
Moscow has a population of about 25,000 and Pullman's is 35,000. You have 2 high-level research universities and all the benefits they bring within a small area. It's a very unique setting. Though Pullman has a larger population, the better retail and dining options are found in Moscow because of the lower minimum wage and taxes in Idaho. Moscow has a mall, though it's fairly pathetic. You'll find most of what you need in the area though. I managed for 4 years just fine, and I'm not a small town guy. Moscow is overall a nice little town, with a decent downtown area for its size. Some good coffeeshops and local stores, restaurants, whatnot. I enjoyed it.
is about 40 minutes south on US-95. The city is larger, and will give you a bit more in terms of retail and shopping. Spokane has a population of roughly 205,000 and is an hour and 45 minutes north of Moscow. Despite being a dirty, rundown city for the most part, it has a couple of good malls, and you'll probably make a trip every 6 weeks or so, That seems about average for WSU/UI students.
Moscow is considered liberal for Idaho, and is sort of an artsy town, if you're into that kind of thing. There are tons of lakes, trails, and whatnot in eastern Washington and north Idaho. The options are limitless if you're an outdoor enthusiast, and skiing is not far away at Mt. Spokane. The summers are hot and dry, the fall is beautiful, winters cold and snowy, and spring is usually mild and wet. I had a great time in the Palouse, and I would recommend it to just about anyone.