I've been to The Wall twice, including my visit to DC last year. We didn't do the Mall this year, we were just passing thru in front of the Lincoln memorial on our way from the metro station to the Korean War memorial that is new and wasn't open last year.
We visited places I'd not been to before. The Native American museum, Capitol Building, Supreme Court building, Botanical Gardens, Library of Congress, Korean War memorial, Pentagon 911 memorial, my son's workplace, his girlfriend's work place...