First, it will help to know what your hospital has to provide so you don't pack too much.
Our hospital had everything but the clothes for our little guy so we only packed some pjs, a going home outfit, car seat, and two blankets.
As for my stuff: hospital had everything from pads (which their's work way better than any store bought), undies (crazy but comfy... I kept my two pair and wash by hand so I don't have to wear my own yet...especially nice after my c-section), hair dryer, towels, blankets, pillows, snack bar, nipple cream, the works...
So I just brought my own clothes to wear home, slippers to walk down the hall in, a blanket for my husband, tooth brush, toothpaste, shampoo, body wash...I forgot my hair brush but they found me a pick...with my long curly hair it was hard to work with though
I second this. Call you hospital and ask what kind of stuff they give you to take home before you start packing your bag. And leave PLENTY of room in your bag or bring an extra duffle to take it all home in. When I had DD, I really didn't know what our hospital gave moms to take home...holy cow! I brought home a bag of monster menstrual pads, panties, nip cream, receiving blanket, snacks, tooth brush, tooth paste, shampoo and conditioner, diaper cream, a few diapers, box of wipes, 2 cozy hats for baby, and an entire gift bag of new clothes, and hand knitted blankets (at first I thought they made a mistake by giving me this, thinking it was for low income moms or moms/babies with issues or preemies maybe but nope, all new moms get one!), plus all the flowers and balloons/gifts from family and friends that came to visit.
But, for me, I was glad to have my own toothbrush, mouthwash, shampoo and conditioner, and what not. Don't forget cozy socks or slippers that you don't mind tossing once you leave the hospital. I forgot to pack them with my DD and ended up sending the hubby out for a pair a few hours after we arrived.