Audiophile paradise. Boasting one of the coolest looking and beautifully crafted sound-systems I've ever seen. More listening bar than club, it has a low key vibe with a diverse roaster of talented DJ's spinning an eclectic mix of tunes and full albums.
The many book stores dotted along this strip can provide hours of inspiration. Aside from those selling new books, several specialise in second-hand and antiquarian books.
Great little cinema, hidden away in the basement of Aubin & Wills, London. Not exactly a fan of the brand but the cinema is pretty awesome. They show a variety of interesting films and have probably the comfiest seats including armchairs and sofas. Bit dear, but one of the best cinemas I've come across.
If you want a peaceful day out of the busy city, Highgate doesn't really feel like London. The cemetery is interesting and peaceful, there's a tour of the old half which is definitely worth the money. Karl Marx, among others are buried there.