Hi kanon~
Just to note. I thought the game was called Skrim till the day it came out.
I remember downloading the Oblivion demo but not liking it at all, so I never bought that game.
I later played a lot of Fallout 3, so that is probably why I'm more used to the playstyle of their games now.
I think the biggest thing you'll decide is if you'll get the PS3/XBOX or the PC version.
Course, pc is cool with all the nice mods. But you will also need to be sure your PC can play the game.
And you will need to think if you'd like playing it with keyboard/mouse or controller. I've switched to controller for a few days and found the loose controls have made me more lazy and careless.
Playing with k/m is a little tiring, but the controls are more precise. So I might switch back after a few more days.
Or you could just hear what the developers think is cool about skyrim: