some responses here
Lidl is perfectly fine, have not been to an Aldi here yet but I imagine it's the same as in Germany. Their products are just as high in quality as the other supermarkets, they have improved immensely in the past few years and sell brands (eg Nutella) and also produce much cheaper than their competitors but it's just as good.
I do a combination of Lidls, Waitrose, Tesco and Sainsburys depending on whichever is closest or what offers they have on at that time.
Iceland is the pits. Morrisons does not appeal to me at all. M&S is too expensive for me.