Lived there for 3 years...
Try to get up to Roundtop Drive and hike the "hidden" bamboo trails.
Get up to Punchbowl, very cool veterans cemetary.
Of course you probably have hit all the other touristy spots, Waikiki Beach, Haunama Bay, Arizona, North Shore, a laua, etc...
Eat at the Wisteria, Yummis, and get an authentic Korean Plate lunch at a roadside shack. Try the Hulihuil chicken if you can find someone stopped....
Excellent diving on the West coast by the power plant, they have sharks.... BTW AFAIK Pearl Harbor is the largest breeding ground for Hammerheads, (the big ones not the bonnets)