Just down the road from where I live is this Art Deco cinema where mainly locals go. Watching films and sitting in this old theatre really adds another level to the experience.
The Royal Park offers great views of London and the city; As well as housing the Royal Observatory which includes a museum of astronomical and navigational tools, part of the National Maritime Museum.
The V and A houses a public collection of prints and drawings of every kind imagineable from old master drawings to photographs, playing cards, fashion plates and wallpapers. You have to select what you want to see from the collection http://collections.vam.ac.uk/and book in advance. The behind-the-scenes route up to the study room of v and a is a treat alone (pictured)