What is a good rpg for 360 or ps3 beside the elder scrolls series?

I have been in the mood to buy a rpg game and i already have the elder scrolls series and i also have mass effect. The only reason why i want an rpg is because it keeps u busy and time goes by fast. but only if it is a good one. Is there any game out there like oblivion where u can explore and free roam cities? and do missions or quests? Thats what i like.