I always add some milk, even though it says not to - less calorific than using two sachets, but creamier than when made with just water.
I use the jar rather than the sachets. Then three heaped teaspoons of powder makes a good mug full.
My favourite flavour is Go Bananas (although I can only find that in sachet form) I also like the Irish Cream flavour but haven't seen it for ages.
Tesco seems to have a limited range of them. They don't do the Turkish Delight one either.
Has anyone tried the Cracking Hazelnut flavour? That's nice. I don't feel the need for milk with it either. Like Cherry, I tend to buy the tubs now so you can have that little bit more than you would in a sachet.