I'm not sure what you mean by advanced. Have you done a lot of yoga already or are you very fit from other types of exercise?
Although I do not consider myself to be advanced in yoga, I do Cathe DVD's almost exclusively and consider myself to be advanced as far as fitness videos are concerned. I'm also pretty flexible. In any case, my current favorite power yoga DVD's are:
1. Eoin Finn - POWER YOGA FOR HAPPINESS and POWER YOGA
2. Bryan Kest - 1995 Series (ENERGIZE, TONE, SWEAT)
3. David Swenson - SHORT FORMS
4. Baron Baptiste - SOUL OF STRENGTH
Segments of other yoga practices I like to use as add-ons (10-30 min) are in the following DVD's:
1. Patricia Walden - YOGA FOR FLEXIBILITY (originally released in 1992, but now a bonus segment on YOGA JOURNAL'S YOGA FOR BEGINNERS)
2. Rodney Yee - YOGA FOR ATHLETES and YOGA FOR ENERGY
3. Sonic Yoga - TURBO FLOW
Among it's many other benefits, yoga will improve your flexibility like nothing else!
HTH!