What's necessary on registry?

I have a couple baby showers planned for me and many are asking for a registry so they know what to buy, but what exactly is necessary? I plan to breast feed, so what brand of pump is best? Should I get manual or electric? but I have no clue about what diaper brand is best/to ask for? What brand of pacifiers? What brand of wipes? Stroller?

husband and I are buying the carseat, crib, and anything we dont get through the baby showers. We will be blessed with whatever we get anyway.

Before you comment:: I can research all of the above questions and I'll see pros and cons of all products, I'd really like personal experiences.