The Elder Scrolls V: Skyrim

The Elder Scrolls V: Skyrim

Pros
No online connection required

Main story centered around good vs evil

Lots to do

Cons
2 evil factions that the player can join, one based around being a thief, the other an assassin. The later which revloves around a ritual that includes chanting and a dead body. The game does portray this faction as bad, but it is something to be aware of.

Things to consider
This game is centered around Norse mythology. While it is not an exact copy of Norse, it takes a lot of inspiration from it, including its own versions of heaven and hell that the player can experience.  There is a few times throughout certain quests that poses the questions of morality and human choice. This is one game that is very much made to allow you to do what you want. If the player wants to be an evil character they very much can side with the evil factions if they so desired. However the game does paint this as something bad by having the player arrested if caught and even having other characters comment on your actions and how they dislike it. There is dismemberment and blood, so if you are sensitive to those you should stay away.

There is a huge modding community, so you should be careful if they install mods. Console versions are much easier to check because it's all done in-game and they have to be verified by the game creators before being allowed.

All in all I think this is a good game to play for anybody who is in high school or older. If they are younger I would advise being in the same room and monitoring them more closely.