The easiest way to give your lounge a fresh look or make a statement is to re-decorate. It makes sense to want a new sofa; after all, it's where many of us spend most of our free time. However, if you want to save yourself some time and money, the best would be to consider the new sofa cover.
Upholstery is by far the most important couch feature from an aesthetic point of view. Unless you are a very skilled DIY person and have a lot of time on your hand, re-upholstering will require a specialist to be involved. You will also need to pay for the fabric. Have your couch re-upholstered every time you feel the urge for the change the colour in your lounge will be completely insane.
A much better and quicker solution is to get the elasticised or fleece cover.
You can have several different colours and change them to match your mood or new curtains.