I love Ocado because of the live stock system, so you know you won't get lumbered with substitutions when your groceries arrive, unlike all the other major grocery home delivery services. I also love the one hour slot (compared to competitior's 2 hour slots). The quality of the food is excellent, the drivers are polite and helpful. My only gripe is poor packaging of desserts (usually on their side, ending up in an unpresentable mess) but this is the same for other home delivery services too.