There are some amazing houses at U of Washington. Here's the SK house someone else mentioned - it really is adorable.
http://students.washington.edu/panhell/SigmaK.htm
And the Chi O house is HUGE. Supposedly it's the largest fraternal structure west of the Mississippi! One of my sisters is the house mom there, so maybe I'll beg a tour from her some day.
http://students.washington.edu/chiomega/house.html