My girls love tinned pink salmon. Whichever one is on offer provided it is not high sodium. They also like sardines in springwater, in preference to the ones in oil. Sometimes they have tinned mackerel, when I can bear dealing with the oil and the smell...they don't seem to like "human" tuna but they like all the Fancy Feast etc tuna-based varieties. I won't feed them anything with colour or artificial flavour. Over here the No Frills varieties (homebrand) of cat pilchards are really nice, whole or big chunks in jelly with no added colours/flavours, for in-between days for me to keep on budget. They like it all

I manage quite well myself on dry crusts and boiled water, with what money's left over.