Hospital Bag Essentials

Bathrobe - I know many sources say you wouldn't want to wear/ruin anything of your own, but I felt so good changing into my own bathrobe instead of the hospital gown and it did not get ruined a bit! 
Socks - Comfy Socks with Grips on the Bottom which turned out to be the best purchase ever for the hospital stay. 
Dry Shampoo - In case you aren't able to shower on your own, this would be a lifesaver. I also brought shampoo & conditioner, which I used instead because I was able to shower at about 24 hours after surgery.
Chapstick, Face Wash & Moisturizer
Boppy - for breastfeeding, snuggling & propping up baby. Can't say enough good things about these!
Camera, Phone & Chargers for both - for sharing the news & capturing all of the first precious moments!
Hand Sanitizer - For you & your guests, threw this in the bag last minute and we went through an entire bottle in three days.
Pillows & extra blanket - for the hubs window seat/bed :) 
Snacks - Our hospital food rocked, but we also had jello, pudding and all of the stuff to make sandwiches while we were there. Of course hubs had to make a Chipotle run on day three as well.
Nursing Bra & Soothies
Baby Hats! - Was so exciting changing her out of the hospital hat and into her adorable hats I brought, and we got sooo many compliments from the hospital staff on how cute she looked
Going Home Outfit for Baby - something comfy & warm. Also, that is the only outfit she wore during the stay, the rest of the time she was in onesies from the hospital or just a diaper. No need to bring multiple changes of clothes.
Going Home Outfit for You - I recommend anything loose, five times larger than regular size, etc. As I mentioned, I was sooooo swollen from the fluids (not just my belly) and could hardly squeeze into the clothes I brought. I recommend Dance Pants from the Gap (I have so many pair, which I wore for weeks after Harper was born) and a stretchy nursing top... or if it is summer, definitely rock a maxi dress!!
Things that I thought we'd need but ended up getting/using from the hospital included the breast pump, lanolin, bottles, pacifiers, swaddle blankets, onesies, diapers, any feminine products, water cups & towels. No need to pack any of those things.. the hospital should be very accomodating! 
And the one last thing I would recommend that we did not bring but it would have been a lifesaver... a plug in night light! All of the hospital room lights are soo bright. At bed time, you still need to be able to see your little one or be able to see to get around, but it is impossible to sleep with the awful room lights on.. or even the bathroom light. So I would bring a small plug in one, you'll be glad you did! :)