I have owned this game on the Xbox 360 but it was so good that I got it to the One too. It comes with all the expansions and the ability to mod. Great fun and addictive!
The game world is huge. The environments are varied and the possibilities are endless. You can basically do anything. According to me this is the best RPGn out.
Graphically, however, it is outdated. But aside from that, the game is a masterpiece.