Here is a list of excellent yoga classes I have found:
Yin Class great for getting over low back pain and not too intense, very relacing and calming.
Sore muscle relief and release
Great if you run long distance or sit for extended periods during the day
35 Minutes Great flow for Hips and Legs
1 Hour Hips Vinyasa Flow
90 Minute Full Body Yin (Long Poses)