As I've done research for Ernie's, I have been extremely impressed with what the UK grocers have accomplished (led by Tesco). If I had to pick a single grocery supply chain as our "gold standard" to emulate, it would definitely be Tesco.
Something like Ernie's would be ideal. It'd even be worthwhile for collecting a few day to day items. I'm surprised Tesco hasn't done this already.
We do really good food, 1-hour delivery windows, and same day deliveries for no extra if you order before noon.