I've always found trying to calibrate my TV by just fiddling with the picture settings to be less then desirable. I know there are calibration discs you can get, but I don't have a Bluray player so that was out of the question.
Over at the AVS Forums someone has put together a bunch of files for calibrating your display (brightness, contrast, colour, tint, sharpness, etc). Here is a link to the thread:
http://www.avsforum.com/avs-vb/showthread.php?t=948496
There are a few burnable disc images, but you can also grab just the MP4 video files.
http://www.sendspace.com/file/abv0dz
The manual on how to use the calibration files is here:
http://www.avsforum.com/avs-vb/attac...2&d=1248641015 (I think you need to be an AVS Forum member to download it)
There are several files in the download, but the "Basic Settings.mp4" is the one I've started with. Simply put the MP4 file in your SageTV imports directory, play the file, and follow the instructions in the PDF manual.
After running through the basic settings, I'm happy to say my LCD has never looked better.
My contrast, and brightness settings were off by a bit. Also, I discovered my TV was overscanning the image when it shouldn't have been.