Most people have a fridge not because they like fridges but because they are a fairly essential domestic appliance.
It's hard to ignore a large humming object in your kitchen, so why not put it to another use, like a pinboard?
Cut out little stencil shapes and then cover some magnets with vintage fabric to attach them to the fridge
Keep an eye out in op-shops for vintage shopping lists - always useful!
Rummage through old photos and rotate your favourite ones
Lovely old postcards never go amiss either
And, of course there is always the practical option - a calendar, timetables and random notes