[Jeffhs]

I think most flat screen TVs can be set to display full-screen, even during commercials. It just takes a bit of fiddling with the zoom adjustment. My flat Insignia 19" set has a menu option in, I believe, the main setup menu labeled "auto zoom"; when this is switched on and the image zoomed in (using the zoom button on the remote) to fill the screen, the picture will do so on everything, including commercials.

With Blu-ray players, as VK member lnx64 noted, there is usually an option to set the aspect ratio for either 4:3 or 16:9, which will cause the image to fill the screen with no distortion. The auto-zoom function (and the zoom button itself) on TVs so equipped, however, will do so by expanding the picture so that part of it will be off the screen. However, since most major network programming is now 16:9 HD and most viewers (except VK's antique TV collectors) have ditched their old CRT 4:3 sets and now have flat screens, the auto-zoom/zoom features have little use except for cable channels that still show some programming in 4:3 SD. USA network does this with Law and Order and possibly other shows filmed in this format.