What is the most impressive answer for "Why you left you current job"?

If I were to be asked by that question I would rather say that I dont feel like I will grow and learn a lot from my previous/current job since I cant see any challenges anymore. I will also state my job responsibilities that I think are irrelevant with my desired task. And also, I am looking for new and bigger opportunities that will help me gain experiences to deepen my knowledge and further my career.

Just that i had never been to Dubai, and i wanted too be, and gain more work expirience 

Well the most common answer that i have heard during the course of my career is that "I am looking for a better opportunity" or "Growth" , this is an acceptable answer but not an extraordinary , appealing or a convincing one because in my point of view it is taking an easy way out.

Candidates should be able to explain their work situation and how it was inconsistent to their career needs and how significant it is for them to look for an employer where they can have their needs met as well as contribute to the competitive advantage of the organization.No organization is going to hire you just because you are ready for a particular position hence you need to explain your needs ( recognition , growth , better compensation/rewards, new challenge etc) in relation to the needs of the organization (operational effectives , competitive advantage).