Derren Brown is an illusionist (or hynotist or mentalist); call him what you will, he is truly AMAZING. I first saw some of his shows on tv last year and I have been hooked ever since. You can watch highlights of his shows on his Youtube video channel: http://www.youtube.com/user/OfficialDerren. There are many videos of his here as well: http://www.youtube.com/user/TheHypnosKing/videos. Or you could simply search 'Derren Brown'.
His performances aren't just for entertainment. He demonstrates how our minds plays tricks on us, how our subconscious mind dictates our behaviour and how we can radically improve our lives if we change our way of thinking.
Just to give you a taste, the following is an episode of his show Trick or Treat, divided into two parts.