In an interview, What is the best answer for the question "reason for changing the current job"?

Firstly, do not say any bad coment about your current employer. You can say as I evaluate my knowledge, skill and experience this position is very suitable to me because I belief I will be able add value for your organization. 

Truth is the best anwer for such question. If you are not getting along then do not bad moukth your old organisation only say that you are moving out due to personal reasons. If it better opportunity or growth be frank. If it is a reason which you cannot divulge then be candid enough to say so. Interviewers like person who are frank and speak the truth.

Dear for this question noting could be the best answer but we have to mind following –

Never give bad feedback about you last company

Never give bad feedback about yours superior

Money is the important thing but it cannot be the only thing