Having switched from a 50" LCD monitor for 360 to a 1280x768 on PC, my PC still looks better than TV ever did.
the metric here is resolution : physical size.
so HD is 1920x1080. if you streach that over a 24" monitor its going to look leaps and bounds better then the same 1920x1080 pixels over a 50" area.
Upgraded from a 22" lcd @ 1680 x1050 to a 27 " full hd about a year or so ago and it was totally worth it.Placebo effect? Not hardly. Don't knock it until you've tried it.
For skyrim specifically, it is. the game itself does not support 1080