My hospital recommended Medela bottles. Something about the teat length being more compatible. Tommee Tippee does one as well which is supposed to be more like a breast shape 'closer to nature' my hospital also recommended it. I agree with the other comments about expressing into whatever bottles the pump comes with and tipping into the bottle you want to use. Also, I definitely agree with Fleur's comment about not introducing the bottle too early. There are probably a number of factors relating to me and my bub, but one factor that probably hindered getting BF established was introducing the bottle really early due to BF problems. I think it compounded our problems but at the time I felt I had little choice.