empty space where nothing looks right!

thank you for all suggestions, the problem has resolved itself as we have decided to knock down the wall dividing kitchen and dining room and the radiator will need to be moved to where the fire once was!

My OH converted the fire opening to hold the TiVo box and DVD player, so the TVs is above them. The shelves that are in the fire opening extend to the edge of the chimney breast. You have to be good at electrics to wire this all in.
PM me if you want pics. You will have to be quick or wait a while as I'm off on holiday tomorrow.

Change the mirror for a painting/print.

A small bookcase?

A small table with an impressive lamp?

luckygirl yes that is exactly what it looks like - in fact it feels rather like the lid may open at any moment and a hand appear over the edge!
The actual hole is no longer there and the breast has been papered to match the rest of the room

The blanket box with candles sounds a tad funereal!

Do you still have the "gap" where the fire was? If so, how about using it to store wine. I have a former fireplace in my kitchen and that's where I keep my red wine and spirits in an attractive wooden wine rack.

I wouldn't have anything symmetrical. What about a tall plant (like a peace lily) or a tallis table lamp. If it's where the fire place was it was presumably a focal point so it probably needs something with a bit of 'presence'. Or lose the mirror. Let us know what you come up with.