Lip balm, phone charger,slippers, nightie that snaps or zips in front, pillow to splint abdomen. As for food. Some protein shake sample packs. Don't invest the money in a whole canister until after surgery, you will only end up giving away expensive powder that you hate. Few cans of broth, 1 box sugar free Popsicles, 2 boxes of sugar free jello, 2 bottles g2 Gatorade, Kroger carbmaster skim milk. By the time you finish that you will be back to driving.
Food scale, measuring cups- just get your own set cause you will just battle your family for control of them if anyone else cooks.
I have the oster blender and like it but the screw on snap caps to make your shake portable are crap, your shake will squirt in your face when you drink it and they leak horribly. I just dump my shake in another container for drinking.

For all those that have already gone down this road, what did you take with you to the hospital that you found you didn't need OR what didn't you bring that you wish you had?
I packed light and was glad for it. I wore home the same stuff I wore to the hospital - loose empire waist dress and a cotton, fasten-in-front leisure type bra. For women, you may end up with incisions right at the bra line and something like an underwire will hurt! I also brought a couple changes of undies. I brought non-skid socks but didn't need them as the hospital provided them. I didn't need pj's or a nighty or anything like that because the hospital provides gowns which are designed to accommodate things like IV lines, drains, etc. I brought my phone and charger and used them. I brought my Kindle but only used it because my surgeon was running late and I had time to kill in pre-op. I brought and used lip balm. Everything else the hospital provided.
How much did you stock up on before and what all did you stock up on?
I got lots of protein SAMPLES, including savory stuff like Unjury chicken broth and HealthSmart protein soups. Different flavors of Powerade Zero and G2. Crystal light type packets. SF jello and popsicles. Different types of tea and broth.
This weekend I bought my 1st Oster personal blender (with an extra bottle), I haven't opened it yet because I wanted to get peoples ideas and opinions before I used it.
I have to tell you, I bought one of those blenders and it put way too much air in my shakes. It made them very foamy and frothy, so basically impossible to drink post-surgery. They were full of bubbles and foam even after I put them in the fridge to rest for a couple of hours. I switched to a Cuisinart hand/immersion blender which puts no air in the shakes and that's what I have been using ever since.
This is the blender I use:
http://www.amazon.com/Cuisinart-CSB-75BC-2-Speed-Immersion-Blender/dp/B00ARQVM5O/
It comes with a beaker to use in mixing shakes.
A couple of other things you may want to have on hand if you don't already - a heating pad (helps your tummy feel better) and a digital food scale.
Good luck!

My suggestion would be, if you have someone going with you for the day of surgery, keep things to a minimum - last thing you want is for something to get lost in the shuffle between preop, OR, PACU and post-surg. have them hold onto your goody bag until you're in your final room - will definitely want your cell phone/charger/tablet (whatever it is you can't live without), book to read, favorite pillow, underwear, pjs or sweats (comfy, not cute). as for CPAP - it depends on the hospital. some hospitals are picky and only what you to use their equipment rather than have you bring your own. if you're picky about your mask though I would bring that. keep it simple, especially if you're close enough that someone can run back to the house for whatever if you need it.

I just had my husband drop me off at 5 am and come back after work. There was no point in him wasting time in the lobby. my surgery was at 7am I didn't wake up 'till 3:30. I became lucid around 5:30 about the time he arrived. I sent him home 10 min later so he could get dinner and get to bed on time to take the kid to school the next day. He picked me up after work 2 days later. He never missed work and was occupied so he didn't worry. I kept in contact thru text messaging my family and friends. I was too busy to be lonely.

You can get that Cuisinart immersion blender at places like Target and Kroger, not just online.
For protein powders - they do sell them at Walmart. A lot of people get and like the Body Fortress brand that they sell there. However, you can't sample anything from Walmart before you buy it, so you could end up with a 2 lb jug of protein powder that you hate. At places like GNC or Vitamin Shoppe, most of them will blend you a sample to try in the store before you buy it. Or you can buy samples online from places like nashuanutrition.com or vitalady.com before buying the same brands at GNC.
That said, I may be over-complicating things - many people rave about the Body Fortress brand.