The International Film Series has been showing art films in Boulder since 1941. They've been in Muenzinger Auditorium on the CU campus for most of those years. (They had stadium seating decades before it became a trend.) In 1998, Muenzinger was remodeled with new seats and acoustic paneling. In 2001, Muenzinger was fitted with Dolby Surround. Independent films in Boulder have never looked or sounded so good.
Caveat: Parking can sometimes be a hassle, especially if there's a football game that weekend.