Thanks for the Liu Chengde links.
He's very good.
My favourite 'unwatered down' Tai Chi exponent Ma Yueh Liang.....also well worth a look.
http://www.youtube.com/watch?v=RHQv6fLpIoI
http://www.youtube.com/watch?v=0fIucL-Q ... re=related
http://www.youtube.com/watch?v=wk4jjrrF ... re=related