i must say I cheated and tasted martin's ensure. I did like the vanilla one and the chocolate, but the most foul one was orange. That was horrid.
We have Nutriment for about 70 cent a can, it taste nicer than ensure and they have chocolate and vanilla and strawberry too. It's a meal in can too. So I reckon it's probably near Ensure. They sell in Asda (which owned by Walmart only is in the UK). It might make a change if you can find it in the US.