If I am to list one of the talks that I will surely miss when I am in London, Ajahn Brahm's talk will definitely be one of them.
Ajahn Brahm is a very inspirational teacher, who shares the dhamma in a light-hearted and joyous way. I personally benefited from Ajahn's talk in many many ways, and cant help to feel very delighted and energised right after.
Do make it an effort to join Ajahn Brahm at Ren Ci Hospital on the 29th March, as he will be enlightening us (as always!) on how to overcome negative emotions. Enjoy :)