Mount & Blade
This game is just...bloody gorgeus and awesome. Its an 3D rpg, where player can travel in a medieval worlds, fight in battles and command armies. It cool and realistically brutal, since there is no magic or anything like that. The battle's are also cool.
There is a demo available, which ends after you gain level six, but the game still has lots of stuff to do. I suggest this to nearly anyone who want an RPG or adventuring.