Tesco (the supermarket in question) has some nice features. The online ordering site is linked to your loyalty card profile, and recent purchases either in store or online are made more prominent. Sainsbury's (also a large chain) may do the same with their loyalty programme, but I don't have experience.

Ocado is also worth looking at. Set up by 3 investment bankers, it sources its produce from one of the smaller, premium supermarkets (Waitrose) but has a (rather funky) purpose built distribution centre from which deliveries are made - rather than having a fleet of picker/drivers at retail stores across the country. Of course, this also limits their geographic coverage somewhat.