I only made my first visit to Troy Bar fairly recently but it's already become a Friday night regular, and I feel like I've wasted a lot of nights not being here. Caribbean food, 4 Red Stripe for a tenner, an incredible house jazz band and as good an atmosphere as you'll find in the city.
The Greenwich Observatory with its green laser beam can transfigure any night sky. If you decide to cross the Thames via the foot tunnel, make sure you look out for the green ray. You can be on one side of the meridian in a minute, and cross to the other side on the next, without even realising it.
The Design Museum is a museum in Kensington, next to Holland Park, which covers product, industrial, graphic, fashion and architectural design. There is also a nice cafe on the 1st floor with beautiful views of the park.