If you are freezing your breast milk, then yes I would buy the medela breast bags since they can store nice and flat without air. I pumped with #1 because the plan was I was supposed to go back to work but I didn't and he never took to a bottle ever. I wouldn't go crazy and say "these are bottles my baby are using" because your baby might have different plans. If you are going to supplement just buy a few that are nursing friend and see what works. I actually used a tiny cup with #1, #2 NEVER touched a bottle. He just used a cup.
You'll need diapers. We use cloth, that is something you want to buy ahead of time and wash and get ready. Not at BRU though. I love our cloth, my newborn/small stash is all ready to go.
Youll need clothes but don't register for ANY. People will buy what they want to. Do not feel compelled to register for onsies or sleepers. I can promise you that you will get 2045720 of them.
Some kind of baby carrier is nice. I have some slings and an ergo. My husband has a kelty which he loves. I don't like wraps personally, i don't like they way they squeeze my saddlebags.
I never went crazy on the plastic baby containment devices. Although, #2 would only sleep in a travel swing (if we werent cosleeping). I had a hand me down one that my inlaws had at their house, which we ended up taking home. I just bought a "new" one at a yard sale for $5, since my last son slept in that thing until 14 months and it was creaking and swaying under his girth. It is old, the new one I got is better and works.
We do have a pack and play, which I didn't have with my first, but having 2 older extremely fiesty boys running around, having a place to put a wondering 4 month old while the other 2 wrestle on the floor seems like a safe idea to me.
I would also think about safety items. We need to get a new safety gate for our stairs. This is a must. A lot of things don't need to be bought but just rethought. Is that sharp cornered coffee table a great idea? How about that glass top side table which is easy to fall over? Save the money on tons of plastic and replace the sharp tables with a nice soft upholstered ottoman to use as a coffee table. If you have sketchy types of blinds that had cords or anything else possibly chokey, I would think about replacing or altering some of that.
We also have a bed rail for our king sized bed for cosleeping - a MUST for us.
I do have a double phil and teds for the boys and a folding maclaren umbrella. The maclaren sits more upright and is for babies 3 months and up.
You'll get lots of blankets so I wouldn't register for any of those.
I did love my Boppy. I have a few and a few covers. I work from home and could nurse my son for hours on that thing. LOVE those. and a regular pillow didn't work for me, I'm a little taller I guess and I needed something firm to push the baby closer to my boobs.
We did get a baby monitor but I never used it really. My babies were always with me.
We have a basic graco snugride for an infant car seat and then upgrade to a britax convertible after a few months. I like the ease of taking out the whole car seat which is great in the winter with 2 other small kids to wrestle out of the car in the snow.
A lot of stuff you don't really need. Bottle sterilizers, washers, wipes warmers, "soothing machines".
I wish someone had thrown me a shower where the things I received were all hand made. There is something special about a nice cotton quilt or blanket and cute knitted hats and sweaters. Much nicer than the 28 silkscreened onsies you'll get from target.