B and I registered for everything, and really early on in my pregnancy, too. We found out I was pregnant about 4 weeks before he was to deploy so I was the very un-pregnant looking girl registering at Buy Buy Baby with a husband who scanner-gun crazy.
Having nannied for 2+ years, I had a really good idea as to what I wanted versus what had just not worked for me previously (Baby Bjorn: Gave me a massive backache and the baby I nannied for hated it. Thus I knew it was a no. Typical stroller-carseat travel system: hated it...bulky, and impossible to push over gravel. Another no. Sleep Sacks: massive YES).
So anyways, I gave B control of the scanner gun and then secretly took items off the registry after he left. In my defense, we registered for a lot of boyish and gender-neutral items. So I replaced, say, dino-themed swaddles with ones that had a girly print.
My biggest tip: for the "big ticket items" (pack n play, swing, bouncer, etc. go neutral. One, they aren't quite as tacky, and two you won't feel like such a fool if baby number 2 is a boy and you have a pink Ergo, carseat, stroller, and pack n play.
These are what I consider your "musts" Obviously you'll still want to register for all the goodies: baby toys, clothes, blankets, sheets, pacis, bibs, towels, diapers...just the fun little things!
Swaddles. E would jerk herself awake for the first 3 months if she wasn't fully swaddled (as most babies do). We went through Aden + Anais, SwaddleMe, and the Woombie. She would get her hands out to her face in all of them; we called her our Swaddle Ninja. Finally at about 3 months we put her in to Sleep Sacks and let her figure out how to stay asleep.
Waterproof mattress pads. Nothing exciting, but a must.
Angel Care Sleep Monitor Of course, now they make one that has a video monitor too. So much easier than having two!
We also registered for co-sleeper and I'm still kicking myself for returning it. My in-laws have this thing about all the grandbabies using the same bassinet. Which is great, except for those first few weeks it was a massive pain to have to get out of bed just to pick her up 90 times a night. She might as well have been in her own room. This was the biggest reason we transfered her to her crib at 5 weeks old.
Britax Chaperone. LOVE this carseat, however when it's on the base it's SO long! It fits great in hubbys truck, but in my 4Runner it's a tight fit.
Baby Jogger City-Mini GT. My true love. We almost went with the B-Agile, but the City-Mini was just better. I used to run with it before we got the jogger. It's light and just perfect.
Baby Jogger Summit XC. Amazing jogger. We bought it used from B's sister and are super happy with it. B likes it because it "fits him better". I use it on my runs every morning and my only complaint is that it's heavier than the City-Mini. Not a "need", since we have the City-Mini.
Car seat attachment so you can put the carseat on the stroller.
Infant body insert-any brand will do. I used ours in the stroller starting at 3 months (but Izy has always had really great head control. So use your best judgment).
Ergo and the Infant Insert. I honestly use both carriers equally, though the Ergo wins for ease of use, and for having the sun-shade.
Moby. It was easier to use when E got a little bigger. She loves both facing out and in.
Pack n Play. We haven't used ours yet, despite it being set up in our living room. But we are traveling later this month so it will finally get some use!
Snug-a-bunny swing (or whatever. It just needs to swing and have a mobile). We would never have bought this on our own because it's so expensive. But we are super happy to have it! I can strap E in and clean and cook and she's as happy as a clam).
Bouncer (I bought ours used for 20.00 since I knew it would have a limited time of use)
Tummy time mat + the extra little hanging toys. This isn't the mat we have, but you get the idea.
Exersaucer starting at about 4 months.
Teething toys...you'll need them sooner than you think! Sophie Infant Teether has been a favorite because it's so light and easy to grab. Lifefactory Silicone Teethers are great, too.
Board books/any books with high-contrast pictures
Every baby is different. E has super dry skin, so I actually use my body lotion on her since the baby ones gave her horrible baby acne. But you'll still want to register for different brands since eventually you'll use them! We use (and registered for) Aveeno Soothing Relief baby body wash, and California Baby on her hair
The most expensive breast pump you can find. Seriously, this is the only area you don't want to try to skimp on. I guess some insurances' cover pumps 100%, so be sure to check that out!
Milk bags if you're planning on pumping at all. Brand isn't important.
Bottles...ok, all the blogs and books say to register for "gift packs" of multiple brands so you baby can choose what works for him or her. We got like 7 Avent bottles just for registering at Target and Buy Buy Baby, as well as the "mail in for a free bottle" coupons than came in our registry gift bags. And my OBs office gave them out too. So I just took off "bottles" from the registry and Elizabeth has never known anything different.
A Breast Friend AND a Boppy. I used the BF for the first 6 weeks (basically until I stopped wanting to kill myself from the pain of breastfeeding). It makes it SO easy to support your baby while you are trying to figure the whole BFing thing out. A sweet friend lent me hers and it was the best think ever. Eventually it became too much of a hassle/I was no longer in pain so I moved to the Boppy for ease of use. And the Boppy is still great for feeding, sitting E up against, and for using as a pillow so I can comfortably lay next to her when she's playing on the floor.
A bottle drying rack for all those pump parts and bottles.