Skyrim

Skyrim is the latest one of the five Elder Scrolls. It is an rpg game in which you're a dragonborn and your main mission is to bring peace back to skyrim basically not only there is a civil war going but also there are dragons coming back to life.
 It's only just about the main quest though, mostly people don't even follow it through, because there is so many other things you can do. As an rpg you're able to play it how you want it. Basically you make the story, depending on what you do and how you do it, will depend how certain people in certain cities react. For example you can join The Dark Brotherhood who are assassins, that will make certain people wish you went to hell and certain people fear and respect you. Throughout the game you complete hundreds of quests.
It's a game where you can either play first person of third person depending on your preferences. You can either use one-handed weapons, two-handed weapons, bows or magic. If you don't like to be limited to only one weapon as you level up and use use a variety of weapons all of those skills will improve and make you unbeatable.
Apart from fighting and resolving problems, you can forge your own armor and weapons, make your own potions, invest in a shop, house, get married, adopt a child or two, enchant things, become an assassin, thief, a noble warrior, a magi, you can also mine, chop wood, cook and many many more. Makes the game less boring and plain.
The game expands quite fast, it already has several different add-ons which vary from adopting children, building houses to riding dragons.
I've personally been playing that game for quite a while now and I cannot say that I am near completely finishing it. It's something you get addicted to really fast and spend days and nights playing it without a break.