Supermarket book tables carry paperback bestsellers, children's picture books and colouring and activity books at prices a bookshop rarely matches, and the selection turns over every few weeks. We track Puffin, Ladybird, Usborne and DK titles alongside magazines and kids' annuals at Tesco, Sainsbury's, ASDA, Aldi, Morrisons, Co-op, Waitrose, Iceland, B&M, Boots, Superdrug, Savers and Ocado (including M&S). Whether it's a holiday read or a present sorted on the way round the shop, the cheapest copy right now is below.