One of my favorite investor's is Bill Ackman of Pershing Square. He develops a detailed investment thesis, builds a large position, and is willing to be very public about recommending changes create more shareholder value. His effort on General Growth Properties (NYSE:GGP) was one of the best investments that I had ever seen. This video provides some solid insight into some of his activities.
Disclosure: I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.