It's hard to find consistently good online yoga videos that are also free. There are plenty of yoga instructors putting their stuff on YouTube but quality can be uneven, and I find they're usually trying to get you to pay *something* in the end (ie, for online coaching, yoga training, etc.) Plus, any one instructor is unlikely to be able to produce enough videos for you to get both breadth and depth in various styles.
I really enjoy YogaGlo and find that the $18/month subscription free is well worth it. And let me preface the following by saying a) I'm not getting paid to shill them and b) I rarely recommend stuff like this unless I'm really impressed. Their site has something like 3,500 classes at this point, ranging from meditation to yoga to mat Pilates. Their instructors are excellent -- these are some of the top names in the yoga world (Kathryn Budig, Jason Crandell, even freaking Tias Little who's a living legend). They have classes in all styles (including a significant number of Ashtanga classes which you don't often see), ranging from 5 minutes to 2 hours. Production quality is quite good -- most of the classes are recorded in their L.A. studio so they have actual students taking the class and being filmed, which is nice because you can watch them if you need to follow along. Most importantly, their search tool is excellent -- when I want to take a class, I just click on various filters until it generates a list of videos that meet my criteria (example: 30 minutes, yoga, level 1-2, hatha style, focus on hips). I rarely take the same class twice because I keep finding new ones that I want to try.
Anyway, I know monthly subscriptions are generally unMustachian, but this is one of those that can be worth it for the quality of the product and the overall benefit to your health, if you have or want to have a regular yoga practice.