I'm a fan of the Carlos Machado - Infinite Jiu-jitsu series as well as Saulos Revolution 1 and 2.
Xande has a pretty complete set as well
I think it really depends on whether you're looking for a 'whole game' dvd set, or one that's specific to 1 or 2 positions.
If you're looking for a 'whole game' set, the poster above has provided some great suggestions. I would also recommend looking into Demian Maia's sets.
Cyborg's Guard Set
Demian Maia's sets
Jacare
Galvao
All sets above are good, if you're a bit more advanced I really enjoyed both Robson Moura's sets and Cobrinha's