Quote: "Boy, I really am behind, as far as I'm concerned plugging it in to a standard TV looks fine. Is this digital and HD stuff THAT much of a difference?"
If you have Half-Life 2, or even better Doom 3 (and a fairly powerful pc)...
play through a level at 640x480/768x480 then at 1280x1048/1280x720
previously games like Half-Life(original) upping the resolution just ment less jaggies in the graphics output, but with Shader games the difference is the depth which the Shaders output at.
The more screenspace the better definition a Shader Surface can get. I mean I'm sure you've seen Gears of War television adverts (the one with the R.E.M. song), and also played it on your television.
You can clearly see on the advert there is a difference in how chrisp the shaders look, leaving you wonder when playing at an SD resolution given the TV advert is in SD (but rendered from HD output) why you're TV can't do that.
The difference in graphics for just the Shaders alone is incredible, but then also take into account that your colour depth goes from 4million to 16billion so you have far more depth of colour providing a better picture quality plus the larger resolution means that with the MSAA (anti-aliasing) in GoW the edges look sharp but flawless. Same goes for shadows and lighting, they all benifit from extra colour depth and sharper picture quality.
The difference itself is like playing GRAW or NFS:MW on the Playstation 2 then on the XBOX360-SD. That honestly is the sheer difference in graphics you get from High Definition. Feels like you're playing it on an entirely new platform, and the SD graphics for the 360 are hardly chicken feed to begin with.