Well in my opinion if your PC is capable of running Skyrim I'd choose PC mainly because when (and they will) mods come out, it can be a good addition to the game. But if your PC cannot handle it i suggest 360, unless you want extreme lag, or worse the game not to run at all.
My PC can easily handle it
i5 2500k
GTX 570
4gb Ram
Might be buying a 80gb SSD (not sure yet)
-------------------------
Played on a 32" Samsung tv
My concern is I am not a huge fan of Steam, but maybe I will just have to live with it. Either way it will be a great game on any platform