Normally we advise to eliminate distracting elements behind and around the screen of any home entertainment/theater setup. But the truth is most people aren't setting up their screens to be the center attention of a room, so a preference for the opposite may be true. Here's a super-size way to diminish the presence of a wall mounted HDTV: wall size murals. Another option is to situate a wall graphic on the wall behind your home entertainment room's primary seating; the large presence is just as effective at diminishing the presence of nearly any HDTV.
A pair of resources for browsing wall mural options are:Surface View offers a huge collection of wall mural imagery, ranging from kitschy, to photography, to sophisticated art artifacts. We've always loved the Lady of the Orient and could imagine it working in a home office environment also. Murals Your Way's catalog include a solid selection of nature-themed wall murals, categorized by Forest, Garden, Trees, Natural Landscape, Water, further organized by seasonal scenes. Science and sci-fi lovers could decorate a home entertainment wall or home office with one of 156 space/astronomy themed murals. Carl Sagan would approve.
Or how about a 7ft - 52″ x 78″ Circuit Board print?