We use Garden Grocer for our grocery delivery. They have a larger selection and are more reasonably priced than Disney. There is a $12 delivery charge, but delivery is free for orders of $200 or more. I also like that you can pay via Paypal if you wish so that you do not have to charge the items that you purchase. If the groceries arrive before you do or your room is not ready, they will hold them at Bell Services. They have a refrigerated/freezer area for storage. We had the groceries brought up with our luggage. Everything was perfect when it was delivered to our room - even the Ben & Jerry's!

I would highly recommend them!
Others have used WegoShop and have been very happy with that service as well. With that, you have the opportunity to make your own list, brands, sizes, etc., as well as designate where you would like them to shop for you. Although I like the concept, I am too lazy to go to all that trouble to make such a detailed list.
For items that you may not particularly need a whole jar of, I have used Minimus Biz to purchase individual sized items. (Packets of mayo, salad dressing, jam etc.) I couldn't see the sense of using half of something and then just throwing it away. They have a great selection and are reasonably priced. I just had the box mailed right to the resort and it was held at Bell Services for me.