On a budget, The Kennedy Center still earns its price.
Free entry/terrace; shows ticketed
The river-facing terrace and the free 6pm Millennium Stage performances make it a lovely, low-cost evening even if you don't buy a ticket. The catch: it's a hike from the nearest Metro, the building's 1970s marble-slab style isn't to everyone's taste, and the headline shows are full-price.