Bryan Kest all the way!!! I would suggest his 3 dvd series called sweat, tone and energize. Also, Baron Baptiste has a good one also, called Long and Lean yoga and it is pretty tough as well. Some people don't like Bryan's style and if that is the case, I would go for Baron. They both give great yoga workouts. Also, Eionn Finn is really really good as well. Good luck!
Susan