I live in DC. Here are some of the things I never get tired of seeing.
  1. The Vietnam War Memorial
    I have no words.
  2. The Korean War Memorial
    Go at night. Larger-than-life grim-faced soldiers walking point through rice paddies of granite and juniper, their faces lit from below by eery greenish light. And at the head of the point the words Freedom is Not Free. Faces acid-etched in a granite wall along the side of the memorial slowly appear; you don't notice them at first. The effect, especially at night, is chilling.
  3. Albert Einstein statue
    Found it once but not sure I could again. Somewhere off the mall.
    Suggested by @dball
  4. The George Mason memorial
    This is one of my favorites. It's near the Jefferson Memorial, and it's actually kind of hard to find (I stumbled on it completely by accident). A bronze George Mason is seated on a bench, relaxed and cross-legged, with his Tricorner hat and his walking stick on the bench to his right and some books on his left. Like he's just waiting there for someone to join him in conversation.
  5. The National Archives
    This place evokes more emotion in me than any other place in DC. I mean, the Constitution. The Bill of Rights. The Declaration of Independence.
  6. The Library of Congress
    The most beautiful building in all of DC, bar none.
  7. The Supreme Court
    The building's cool (and the courtroom is beautiful). You can tour the public sections of the building on your own. Public seating for oral argument is limited, and it's on a first-come first-served basis. Once the seating fills up, they'll allow people to come in and stand inside for a few minutes just to see what's going on, and then they just file them out again (at least they did that last time I was there).
  8. The Smithsonian museums
    The museums are great. There's something for everyone. And they're FREE (okay they're mostly free; there might be extra things that you have to pay for like going in the planetarium). I've been to most of the museums but not all; I'm more of a walk around outside and look at the architecture kind of girl.
  9. And a ton of other places, like the Lincoln Memorial, the Jefferson Memorial, the World War II Memorial, the Washington Monument, the Capital, Lafayette Square, Ford's theater, The White House, and the list goes on and on.