The nunnery is great - great view and juxtaposition of the site's buildings with the towers and such from the rest of HK. Also a fan of walking along the harborfront (TST side) at night, then skipping over to the island and exploring a bit more. The buildings are beautiful and stuff like the HSBC building, you really don't see anywhere else. In terms of restaurants, I had a fantastic meal at Hutong when I was there last. Great seafood up in the Sai Kung area, as well... in addition to nice hiking and general outdoorsy stuff.