What is the most fun game in the world

It really depends what kind of game you like and if you want to pay, for example, if you like fantasy adventure rpg's I would say try Dragon Age or Oblivion (if you like first person). If you don't want to pay than I would say Dragon's Nest. Or if like dirty humor (like me :P) I would suggest Duke Nukem Forever. If you like Gun's and FPS games than try out Call of duty, or if you don't want to pay any money try out Combat Arms. Or if you like freestyle Multiplayer games than try out minecraft (It costs about 21$ CAD )
Hope This helps