You can never have too much storage ... and a few mirrors help as well. Virtually all areas of the home benefit from mirrors:
Hallways: For most of us this is a small narrow space which can always be improved by a mirror. It fulfills many functions here, statement/artwork, final check before going out the door, space enhancer and light enhancer. Combine with a small table and flowers. I've said it before but how can you go wrong?
Bathrooms: An equally deserving space - a mirror is pretty essential here as well as making the space feel bigger - it can usually be combined with storage to kill numerous birds with one stone.

Living Rooms: if you can't afford that artwork you lust after, choose a beautiful mirror. Make it large scale and prop it up against the wall, place in alcoves, or hang multiple small ones to create a feature, choose a material or shape that links with the rest of the room.
Bedrooms are a useful place to have a full length mirror to check that your outfit looks ok. I once went out with two different shoes on - failed to do the mirror check that day but luckily I did not have an important meeting!