If your PC is strong, and I mean REALLY fucking strong, then buy Skyrim for your computer. Assuming you can handle it, you'll just get a better package out of the PC version. The graphics are better, the control is smoother, and you have access to mods, some of which may considerably improve the game(But be careful, some of them can break the game to. Always look in the comments section and read the description thoroughly, make sure the mod won't conflict with other mods, and that it's properly working. It will also be useful to know how to remove it without damaging the game, if you don't know how, keep a backup of the game folder(which you should do anyway). At least, that's how it worked with Oblivion)
On the other hand, if your PC can't run Skyrim on max or at least relatively high settings, then you'd be better of with the consoles increased stability. If you can't run the base game at it's best without a problem, then you won't be able to take advantage of mods beyond the occasional new weapon, and the game won't look as impressive as it would on the console.
If you've got a monster PC or feel like shelling out the cash for one, then get Skyrim on PC and enjoy the world of modding. If you don't have one and don't feel like blowing a few hundred bucks, then it's not worth the hassle it's going to take to get the damn thing running smoothly.