I can see the argument already, since I have been in them, "You shouldn't watch Ellen or Oprah"one person remarks and then the avid watcher says, "It isn' that bad, heck I watch it every day and I'm fine." The ironic statement is that we all assume we are fine when we all have many flaws.
This is a good question, "Can a Christian watch Ellen or Oprah and be unaffected by their ideology?" First of all, one has to rephrase the question to "Should." We all can do things and we are free in the Gospel, but the true question is should we. Let's first of all go down the list of concerns when people watch either show religiously:
1) Both women are avid promoters of deism (There is a god or gods out there). Many people mix them up as Christian due to references they occasionally use. This is more of an Oprah issue than Ellen.
2) Both women do not promote family, if anything they promote everything but family. Oprah has been an advocate to not get married because of monetary and feminist ideals. Unfortunately, many could be led to think that marriage does not bring joy. Ellen, well, two women is enough said when it comes to marriage.
3) Both women are very nice. That might seem weird to say, but since they are nice, funny, and dynamic. This can create a problem in that often we assume that nice people must be right because if they were wrong they would be evil and mean. In the post-modern world, how you say something is more important than what you say. One must discern what they say first, especially when they are so darn nice.
Now back to the question, "Should a Christian watch these shows?" Unfortunately, there is no real answer. If you are one that understands what we believe as Christians about God, morality, marriage, sexuality, and the like, then yes. Go ahead and watch these shows to understand what is going on in culture and think of the Christian worldview. I watch it from time to time to see what is going on, and I have to watch my tendency to like what my itching ears want to hear. However, if you are one that questions these things, struggle with a biblical worldview, and feel yourself leaning away from Christian ideas, then these shows are the LAST place to go. Go to the Bible, talk to your pastor or trusted Christian friends, and dig deeper.