I agree with what everyone else has said - there is not a single reader out there that can meet all needs.
It's good to get different opinions from different people about the different readers that are out there. But keep in mind that a reader is a very personal thing, and the features that one person values might not be so important to someone else.
I, myself, am quite happy with my Sony reader. I have had no problems with it and it's the perfect size and has just the right features for me.
I hope you are able to find one that you fall in love with. I'm sure there are plenty of people in these forums who will be willing to help you with your decision