Storage a problem? Try “converting” a wall into ceiling-high bookshelves with storage cupboards below. This may decrease floor space slightly, but will open up areas where once you needed to put your stereo, speakers, television and video cabinets, books, ornaments, etc.
If you have small children, designate at least one of the cupboards (or maybe a very deep drawer) to their toys, so that a quick tidy-up is possible when unexpected guests arrive!