Nvidia or ATI? HDMI connection? If its nvidia, modern nvidia drivers have a HUGE flaw that outputs levels to the TV as 16-235 instead of PC levels of 0-255, the problem with this is 1, your TV is either trying to display at PC levels, meaning anything from 0-15 on the brightness scale has been chopped off and all is being displayed as a dark grey and 2, even if your TV is properly auto detecting limited levels being sent to it, Skyrim is rendering (on the pc) at traditional PC levels, meaning you are losing 15 shades of black and the rest of the spectrum is being "crushed" and you are seeing 0 accurate colors.
To fix this, you need to do an EDID moddification to your drivers. This goes for ALL nvidia user. Using an EDID extractor like Phoenix EDID youd get your TV's edid info,
The easiest way to tell for sure if your TV is affected by this is to go to your nvidia control pannel and look at how your TV is dectected, if its shown as "HDTV" then its being sent limited levels (16-235), if its shown as a PC device of has resolutions listed under "PC" in that resolution list, then its being sent the proper levels (0-255).
Nvidia has known about this problem for THREE effing years, and still refuses to acknowledged it or fix it. ATI fixed it 2 years ago with manual levels selection in there control panel. Nvidia refuses to do it.