We'll start with the obvious..
A bassinet is a good thing if you plan on having baby sleep with you in your room for a few months but its not really a must have because not all parents have baby room in with them. Some start baby out in there crib from the beginning. and obviously if you have a crib you need a crib mattress.
Totally a must have some type of baby swing, They are great for when baby wants to be rocked but you are just to tired to rock baby because your sleep deprived. Kara slept in a swing for like 2 months because she refused to sleep in her crib. Bouncers can work just as well but don't have the swinging motion. Devin slept in a bouncer for 3 months when she was born because she didn't want to sleep in her crib (to make it worse I had to bounce her with my foot while I slept!)
My personal favorite is Aden + Anais they have muslin swaddle wraps that are thin but still keep baby warm, with cute designs. The only downside I found is that you can only purchase them online (at least in my area I can't find them in stores). Carly LOVED to be swaddled especially for the first 2 months.
well this is obvious because you can't leave the hospital without one.
Gripe WaterThis is a Miracle item I would have to say! Does your baby have hiccup's? Then this is the cure for you! Carly has hiccup's A LOT! But just one dose of this and her hiccup's disappear! I guess this stuff is also for stomach problems, teething and colic, I don't know how it works for all of that but hiccup? It defiantly works! I know its not gear but it is a MUST!
Other gear is important but for me these are a MUST, So make sure when you bring baby home you have this stuff ready!
Have a Great Day!
All Images on this page are courtesy of Google Images (well except the very last image is me :)