Northwestern University Theatre - the buildings are a conglomeration of performance spaces which include stately old theaters like the well known Cahn auditorium and Pick Staiger concert hall, to the garage-like atmosphere of smaller places like Shanley Pavilion, known to Northwestern students as the Shack. Northwestern houses approximately 10 theaters on campus, and it's not rare when they are all filled each weekend.
The NU theater department is one of the most highly respected in the nation. (That's why so many movie stars went to NU I guess). They put on dozens of student productions each year. Almost all are of the highest quality. Their offerings range from musical theater to the traditional (i.e. Shakespeare, Chekhov, et. al.) to original plays and more experimental pieces. The University Theatre's box office number is (847)491-7282.