Yang's Teriyaki Plus - At the south end of WOU campus, near Main St in Monmouth, OR
I used to go here almost daily as a student. The food here is cheap and yummy, which are the two things that most college students look for. The staff is super friendly and they have been around for a while. All of this makes Yang's a sort of a legend among students.
The menu items come in two sizes, large and small. I always get the small, because the large is huge.