One (sometimes two) of ours are really fussy about the Hilife and Purely (petsathome's top-range stuff)... they won't touch the Chicken & Liver flavour, won't touch the ones with solid lumps of fish in...

Best results we've had so far has been with the Feline Fayre "Simply" range, and I'm really impressed to see that they're now doing their Tuna flavour in a larger can (not the tiny cans like HiLife Pate; same size as human tuna tins) instead of the landfill-hell plastic pouches.