I want to say I disagree with the poster who advised newbies to go with an alignment based yoga. I mean, how can you learn alignment based Iyengar without a teachers eyes? I leave my Iyengar practice to live classes and my DVD yoga practice is mainly Kundalini which teaches alignment (and many other things as well) from the inside out.
Actually that poster is a very experienced alignment based yoga teacher.
I disagree with your points though. I have learned much about alignment based yoga from using quality videos online, where every muscle movement and bone placement is described in detail so that one can really learn to listen to their body and feel if they are in correct alignment. If you are limited to videos only, this would be my suggestion as well.
I began my own practice with kundalini yoga videos, and tried several by different teachers. I also took a Kundalini yoga class series. I do NOT remember anything about alignment in the class or in the videos. Actually, I injured myself from performing kriyas improperly as there were no warnings about how NOT to do them, and again, alignment was not stressed in any way.
As for Ana Brett and Ravi Singh, the videos can be fun. But yes, they are a little cheesy. I had issues with Ana being very scantily clad and her nipples popping up so they were very prominent, and I felt this was really not necessary, why would you even have that, it was distracting (yes I'm a modest person, and not into seeing other women's nipples poking out).
I am limited to only videos for my yoga practice, and highly recommend you try http://www.yogatoday.com
There is a free 1hr class each week that you can live stream as many times as you like. You can purchase videos for only $4, and you can also subscribe for $10 a month and live streaming of the classes is unlimited then. They have hundreds to choose from.
Neesha teaches Iyengar based yoga - alignment based. Adi teaches Ashtanga and Vinyasa flow, and Sarah teaches Kundalini yoga. I love all of them, and love that I can choose the yoga style I am most in the mood for. I most appreciate Neesha though, as I am trying so hard to make sure I'm always in proper alignment! The classes are well taught, and professional, and most of them are filmed outdoors and are not commercial feeling. Give them a shot, the free classes every week are one good way to see what they have to offer.