I'm a huge fan of paint as the most affordable way to drastically change a room. I'm always talking about 'paint makeovers' and how much you can do with paint. Hopefully these pictures back up my claim. The living room shown above is the same room as you see below, but with furniture. I wanted to show how it looked without any furnishings and decor. This way you can really get an idea of how the paint changed the room.
It was also very affordable, I did all the work myself, so my only cost was paint. I personally removed the carpet and old drapery (in a day) and then painted the walls, ceiling, trim and fireplace in white and the floors in gloss black. At that time you could still buy oil paint, so I put black oil paint on the floors that stood up pretty well over time. The floor paint was smelly and needed a couple coats with a day to dry for each. Over time, the floor paint did chip in places here and there (mostly because I would drag furniture across it). I did consider a lighter colour paint on the floor but at the time I wanted the contrast of black.
Here's how the room looked when I bought the house, with wall to wall carpet. BEFORE:
And the empty painted room and fireplace: AFTER: