Teletubby and Yo Gabbagabba : Parent T.V. Cunundrums

For the very young, television watching is a double edged sword.  In today's family where it is assumed that both parents work outside the home, or a single parent must get through the day doing what they can to get everything done with some sanity, television since its dawn has been a blessing and a curse.
Do I let my child watch shows that I consider rubbish?  What is rubbish and what is educational and helping my child develop their school-readiness skills?
From BBC's Teletubbies to CBS's Sesame Street to Yo Gabbagabba, many children's programming aims to enhance child development, working on simple concepts such as language development, social skills, reading skills, relationships, ethics, pattern recognition, emotions and the like. 
Knowing how it is helping is part of the task of a parent.  Too much of anything is usually considered harmful;  thoughtful and attentive parenting is going to enhance the family system and help a child's development.  This includes television watching and any other form of media that may crop up.  There are video podcasts of sesame street and other children's shows as well, making these a mobile option.
My recommendation is to look into what shows are age and developmentally appropriate, what needs your child has and of course what they like and, if you are open to it, selecting viewing times which are limited and ideal to your schedule.  Televisions should not act as babysitters, but in a crunch as reality will dictate, doing taxes or making that important phone call for the duration of that time period would possibly be a well-thought out plan.  Viewing with your child to be familiar with the songs, the dances and the lessons learned would be of value as well. I personally like the animated shows  Arthur and Franklin, because they are based on books.  The characters  grapple with many common emotional issues.  They also entertain the parent, I have found!