supermarkets then for sure grainger market
but I also recommend tesco and if so get yourself an app (clubcard) coz then you will be able to pay for some things much cheaper and if you collect enough points you will get a voucher. *I would recommend going to the Gateshead one, the big tesco, because well it's big hahaha so you will have much more variety and more things coz the one in town is pretty s***barely has anything in.
As for supermarkets like grainger market, i can't think of any
Lidl is pretty good too but there's isn't any in town, the ones I am thinking of are: the one on old durham rd + near metro centre